The linguistic turn is normally associated with a number of trends and tendencies in history such as Foucault, postmodernism, women and gender history, etc. It generally refers to a mode of analysis where, rather than trying to discover causation, we instead try to understand the meaning of a text. In this sense, the goal is to understand different discourses that are embodied in texts and understand those discourses and meanings as driving forces rather than as merely reflective of some social change. Additionally it is often associated with a move from seeing, say, class as the main site of identity to recognizing numerous different sites of identity (e.g. gender, race, citizenship).

Interesting books on the topic are The Future of Class in History. What's Left of the Social, by Geoff Eley and Keith Nield. Eley along with Richard J. Evans and David Blackbourne were major figures of the social history in German history, and Eley's book is his attempt to discuss the usefulness of class in a post-linguistic turn world, which leads him to a methodological eclecticism (or pluralism), where one can use the various tool sets of postmodernist and social history. His watchword would be "You don't have to choose".

A counterpart to that would be Evans' In Defense of History which is dedicated to opposing postmodernism.

Another interesting book is What is History Now, which asks a number of historians what their field is like now and many mention the linguistic turn (although not all define it). The only historians I've read who contribute are Evans and Pedersen, and both are very good when in their subject matter. (The Guardians, by Pedersen was fantastic.)

As to my opinion, I'm mixed. I think that the linguistic turn produced a lot of amazing scholarship and that most of the gloom and doom that people feared failed to materialize. I am a bit annoyed though that, from my perspective, the linguistic turn took off just as social and economic history was losing steam and while I do not think that one caused the other (if anything I blame the institutional weakness of the new economic historians!). But yeah, generally supportive, but a bit melancholy about it.

Naturally the linguistic turn wasn't just isolated to philosophy. The entire premise of the linguistic turn is that it affected the humanities, most of which are disciplines that are very much connected to eachother. The reason why it's not mentioned as often in historiography is probably because it's being lumped under either poststructuralism or postmodernism, which both had elements that are often being credited to the linguistic turn.

The linguistic turn manifested itself in the discipline of history in several ways. Most of all, it led to the rediscovery of language and culture as "creative" or "lively" factors with agency. This turned the attention of many historians towards more cultural subjects and increased their awareness of the non-static nature of language. When Jonathan Sperper talks about historians diving off the deep end, he is probably refering to those who were influenced by the radical work of Hayden White, or by similar theoretical works. This led to a radical interpretation of the linguistic turn in which history has almost no bearing on reality through it's dependency on language and would in theory be just as fictitious as a novel.

I think that it's rather of unfair to consider these kind of radical interpretations as the legacy of the linguistic turn. I think that it's a lot more realistic to say that most historians evolved in a positive way through the linguistic turn, poststructuralism and postmodernism. Very few historians used it to completly abandon the structuralist or even realist approach, but rather used this opportunity to come to a comprimise. This led to an increased awareness of the subjectivity of language and interpretation, which ultimately forced historians to focus more on reflexitivity and interconnectivity.

I think that Foucault, Geertz and Derrida mostly had very positive influences on historiography and they were very much a part of the linguistic turn, poststructuralism and postmodernism.