As a general rule, I prefer the fiction I read to have a high degree of accuracy. However, over the years as both writer and reader I've come to the conclusion that sometimes too much attention to period detail and language can detract from a good story.
This does not mean I'm advocating fudging history or using obviously modern language, but in certain situations, choosing a better word or dialling back on the period detail can improve the book. One immediate example I can think of is when you use a word that may be right for the era, yet it sounds too modern. This will pull your reader out of the story and only a small percentage of them will check an etymological dictionary to see that you indeed are correct. Most of the others will think you're either too lazy to look up the right word or don't care. Either way, you've pulled them out of the story, the last thing you want as a writer. I ran into this upon discovering that the word "sidewalk" has been around since the late eigtheenth century.
On the other hand, sometimes it's so tempting to use a really neat period word, one that resonates with you. But will it work for your reader? Again, a very unfamiliar word can pull them out of the story. OTOH, used judiciously, and put in context, these words can add historical depth to your manuscript. The key, IMO, is to use them sparingly or risk your reader shutting the book and giving up because they don't want to be bothered trying to figure out what your characters are saying.
The same thing goes for going into too much detail about say a battle, or the process of a handcraft or something similar. Yes, readers read historicals because they love the past, but they also want to be entertained, not lectured. I know just how easy it is to find something fascinating and want to include it in my story to share with others. But I have to stop and think about whether I as a *reader* would be as interested. No matter that it might increase the verisimilitude of my manuscript, if it bores the reader, it doesn't belong there.
So, that's my opinion. What do you think? Is there such a thing as too much accuracy in a work of fiction? Do you edit your work for words or details that, while interesting to you, might make the reader either skip pages or worse, close the book?