Modified from an earlier answer

The effects of the Great Reforms (for brevity's sake, hereafter referred to as GR) were wide ranging and long lasting, but as a whole they do not support the notion that Alexander II was a progressive autocrat. Many of the GR would erode the strength of the Romanov system and contribute to the fragmentation of society that led to both the Revolutions of 1905 and 17.

The chief act associated with Alexander II was his abolition of serfdom in 1861. This had been a third rail within Russian politics for over fifty years. There was a growing consensus within Russian ruling circles that serfdom was an archaic anomaly that was out of place in the contemporary world. For Russia to be European, this logic held, serfdom would need to be abolished. The problem was one of how to get rid of serfdom without alienating the large rentier class of land owners, many of whom the state relied on as servitors within the large Russian hinterland. The GR decided upon an expedient solution of legal emancipation, but hobbled it with a confusing patchwork of redistribution and repayment of the landowners for the land. The GR emancipation created only small changes land ownership for the serf-turned peasant. Few serfs could afford to make the payment for the land outright and the Russian state lacked the resources implement emancipation in a consistent manner. The peasant commune, the mir or obshchina, negotiated with the landlords and ended up owning land and parceled it out collectively.

Coupled with emancipation was a series of localist reforms that granted a degree of autonomy and self-governance. In the Russian countryside, the zemstvo (pl. zemstva) had a very limited franchise but went a long way towards establishing something that resembled a civil society within the Russian countryside. A zemstvo was responsible for local issues and the development and maintenance of the local infrastructure. It also gave peasantry a degree of equal footing towards the nobility (limited, but much higher than prior to the GR). The zemstva were largely limited to the core Russian territories; they were not within the Western Provinces nor in Siberia or Central Asia. Extention of the Zemstava to these areas would become to later Russian politicians as a contentious an issue as that of serfdom a generation before.

The contentiousness of the Western Zemstava issue in the early twentieth century underscores an important aspect of the GR, that the chief beneficiaries of reform were frequently Great Russians, and the imperial state could be quite indifferent to the needs of its various subject populations. In the case of Poland, the attitude of the Romanovs was quite hostile and Alexander II's reign saw some of the greatest restrictions on Polish civil liberties in the aftermath of the failed 1863 rebellion. The era of the GR also witnessed the codification and cementing of a mentality of imperial officials that both its Ukrainian and Belorussian populations were in fact "lost" Russians that had been separated from the Great Russian cultural sphere through both an accident of history and Latin Polish perfidy. The state accordingly began to clamp down on the cultural activities of these peoples in order to hasten their Russification under the auspices of the Romanovs. For example., the Valuev Circular of 1863 imposed censorship and limits on Ukrainian language and printing, with the justification that Catholic Poles were using the language issue to drive a wedge between the tsar and his "Russian" subjects. By the same token, tsarist officials also closed down Catholic and Uniate churches n the Western Provinces and reopening them as Russian Orthodox ones. The unification of Germany also fostered suspicions on the empire's Baltic German population, even though they had been as a corporate group one of the most loyal servitors of the Romanovs. And of course, antisemitism and restrictions against Jews remained in force during the GR. Jews were still not allowed to reside outside the Pale of Settlement unless they had an occupation and even converted Jews found that the glass ceiling in imperial society was very real. Unlike their Habsburg neighbors, the Jews of imperial Russia never really developed Kaisertreu sentiments that looked upon the emperor as a protector and benefactor. Although it has since become clear that the tsarist state did not sanction the various pogroms that occurred after Alexander II's assassination, there still was a widespread rumor that the state engineered this mob action. That such rumors gained widespread currency among contemporaneous Jewish communities demonstrates how little Jews figured into the state's policies of reform.

Within Russian cities and towns, Alexander II's reforms gave a degree of autonomy, but the GR laid the foundations for larger social conflicts. Although the GR allowed for elected city council (Duma) which appointed the executive council and the mayor. The franchise was incredibly restricted and based on land ownership and a series of nebulous other restrictions. This made the political governance of the Russian cities very tense as they evolved into metropolises. For example, Moscow had an odd situation as the new money industrialists often could not vote (they rented often palatial apartments) and the owners of decrepit hovels could.

The most successful of the GR that reflects the notion of Alexander II as a progressive force were the judiciary reforms. The 1864 judiciary reform set up an independent judiciary, a jury system and Russian bar system that allowed for the professionalization of law. The first generation of Russia's nascent political party's leadership came from the Russian legal system. The courts themselves relatively open and were among the freest spaces in imperial society. By the same token, the GR expanded education and encouraged a degree of new thinking in Russia's higher education system. But like other aspects of the GR, the benefits of this new openness were not evenly distributed in Russian society. Advanced education became out of reach for the overwhelming majority of the population.
One of the contradictions of the GR is that they exemplified the state's desire for Russia to modernize but also arrest the social changes that modernity unleashes. This was partly a function of how the Romanovs saw themselves within the state framework. Throughout the GR, one of the sacrosanct elements was the importance of autocracy; neither Alexander II nor his successors would tolerate any reform that ate away at the political strength of the tsar. Alexander II likened his role as a mediator between the various social groupings. This further fragmented political and social society at the expense of the institution of the tsar. The tsar simply could not be all things to such a heterogeneous polity as the Russian Empire. The historian Alfred Rieber describes late Russian society as a "sedimentary society," in which various social identities coexisted and overlapped with one another. The democratization elements of the GR was one layer of these sediments, but this ultimately prevented any widespread social cohesiveness from evolving under the tsarist state.

Why then does Alexander II have such a reputation as "Tsar Liberator"? His assassination certainly added a counterfactual gloss to him, like JFK and Lincoln. Partly this is also a function of the fact that he came between two very conservative tsars. His father, Nicholas I, was a somewhat eccentric tsar who embraced Metternich's system of reaction with a verve and energy that surprised many. Like his Prussian counterpart Frederick William IV, Nicholas I believed he possessed a mystical connection with the land and its people. Alexander III was unlike his father and embraced Bismarckian archconservative nationalism and sought to transform the monarchy into a bastion for the right. Finally, it should also be remembered that the very idea of reform was daunting for any tsar to undertake. Alexander II was able to use the defeat of the Crimean War to transform the Russian state in a series of massive leaps in a different direction. Alexander II possessed a degree of political realism that his son and grandson both lacked. Given how badly Nicholas II reacted to crises in the twentieth century, some appreciation of Alexander II is warranted even if he does not live up to his popular memory.

sources

Clowes, Edith W., Samuel D. Kassow, and James L. West. Between Tsar and People: Educated Society and the Quest for Public Identity in Late Imperial Russia. Princeton, N.J.: Princeton University Press, 1991.

Lincoln, W. Bruce. The Great Reforms: Autocracy, Bureaucracy, and the Politics of Change in Imperial Russia. DeKalb, Ill: Northern Illinois University Press, 1990.

Weeks, Theodore R. Across the Revolutionary Divide: Russia and the USSR, 1861-1945. Chichester, West Sussex: Wiley-Blackwell, 2011.

Wortman, Richard. Scenarios of Power: Myth and Ceremony in Russian Monarchy. Princeton, N.J.: Princeton University Press, 1995.