I enjoyed the book most when it wasn't trying to tie into existing Trek characters. Having a conversation with Captain Picard or bringing Geordi along on an away mission felt too much like b-grade fan fiction to me. But having an original 24th-century ship with an original crew is fun! My other main complaint was too much 23rd-century (read The Original Series) Trek popping up. Scotty heads up the Starfleet Corps of Engineers?! I liked Scotty in TOS and the movies, but he just seems out of place here (just as I felt he was out of place in the TNG episode "Relics"). And a mission to save a constellation class ship? I know it's bad of me as a Trekkie, but I wish we could forget TOS ever happened instead of drudging it up all the time.

TLDR: Great when it's forging ahead as a post-Dominion-War adventure of its own; less great when it's borrowing from existing Trek franchises.