Not a bad one, although as it was early for Trek books, it took a few liberties here and there. "First Frontier" is definitely a fun one, I enjoyed that. Don't listen to your 'unnamed sources', there is a LOT of fun to be had in the numbered books. Not as tight, continuity-wise, as the new books (in fact, they often contradict, unless the 5YM was about 40 years, and Kirk was a bigger menace to the timeline than even hinted at in DS9), but each story by itself works well. Some stinkers as well, but plenty of good stuff there.