There are good academic works on post-Soviet Russia, and they are nonpartisan in the sense that they are not supported by a political party, but even these authors will have strong opinions.

Anyway, here are some options. They're going to be heavy on the political science since that's what I read the most of:

Russian Politics and Society Richard Sakwa

• Sakwa constantly updates this book so it gives a very good sense of the background for the current people and institutions that are important right now. It's very comprehensive (it's a textbook) but is coherently written and has a historic narrative and chapters that deal with different aspects of politics and society. He has strong opinions that I sometimes disagree with but this book mostly stays clear of those.

Understanding Russian Politics Stephen White

• This is updated through 2011. Stephen White has written about Russian and Soviet political processes for years (How Russia Votes, which he co authored and which I am more familiar with, is great and came out in the 90s) and his work is very detailed as to why Russian elites and public make the political choices that they have.

Contemporary Russian Politics, A Reader Archie Brown, ed.

• This is old (2001) but I'm including it because Archie Brown is a venerable Soviet/Russian expert, and because this is a work (a thick volume) that is largely essays by different authors on a variety of topics.

These are all academic works that get used as classroom texts, so they're definitely not written for the general reader. With that said I think they're very engaging (I've reread them for fun!) and extremely informative.

It’s a tough tough one. Most of the western books are highly opinionated/catered for commercial reader. If you actually looking for impartiality there are tons of serious research papers on economic/social analysis of Russian society/modern affairs. The question is what exactly you want to learn and how keen you go down the rabbit hole.