I can't say for sure at this point if the effects of Kindle Unlimited will be long term with my book, but so far, things seem to be going good.
My sales (including the kindle unlimited sales) seem to be back to what they were before.
So I wouldn't say that my book is doing better than it was before Kindle Unlimited happened. I wouldn't (at this point in time) recommend it unless you've seen a significant sales drop and aren't currently selling well on other sites like Barnes and Noble and Itunes.
I've actually been receiving more regular sales than Kindle Unlimited sales since I joined (I was getting very few regular sales before), which makes me think that if you are in Kindle Select, Amazon does things to make sure your book is more visible than those who aren't exclusive, even to customers who are not using Kindle Unlimited.
I would also recommend using either your free days or the discount days to help boost your rank, but if you are using the free days, it's probably a good idea to spread them out and only schedule one day at a time, since the free downloads natural drop after the first day.
I'll let you know more about it as I learn more.
And in the mean time, feel free to share your thoughts on Kindle Unlimited with me as well.