I loved The Price of the Phoenix, the book this is the sequel to, in all its cheesy glory and its slashy subtext. It might have helped I was a teenage girl when I first read it, and a fan of the original series before it was reborn in film and new franchises such as Next Generation. Back then, books like this were the only sign of life, unless you were hardcore enough to send your SASE and check for mimeographed fanzines. Also, unlike most Trek fans, I'm a Kirk fan, not a Spock fan, and say what you will about Culbreath and Marshak, but they give Kirk's heroic dimensions their due. And I think it takes a Kirk fan to "give" the Romulan Commander to Kirk--or rather a Kirk to her. I loved the end of the first book with them off together to change the Romulan Empire, that basically she gives to James the challenge Jim Kirk gave the Spock of the Mirror Universe to summon the future.
So, I think you might guess the problem I had with this book if you've read it. Big time. Like another reviewer, at the end of this I wanted to give "the book a nice heave across the room" when I read the last page. And there's no third book to redeem that ending.