I thought this was an excellent novel and a perfect idea for a franchise that’s meandered all over the place trying to fulfill both new series and continue the older series. The author nails the voices and as you would guess there are a number of familiar figures from both TNG and DS9 and I could hear each actor or actress whenever they were featured. It’s a great tie in to pre DS9 as well as explaining O’Brien leaving, Picard aftermath of Chain of Command and even some insight into Kira. 
My only knock is the author did too many summaries of past TNG episodes and while 1 makes sense I think he did 2 or 3 and that’s just wasted time IMO. I hope we get more books during this timeline (the Berman era TV shows) as there are hundreds of possibilities and authors willing to write them.