As for Titan as a whole, it has indeed had its ups and downs sofar. I'm not a big fan of the works of Michael Martin and Andy Mangels. They just don't captivate me as much with their writing style, even though the stories themselves are more then interesting to me.
Mangels and Martin are indeed a phenomenon. I absolutely love their Sulu-Books "The Sundered" and "Forged in Fire", both among my all-time-favourites. Their Titan-Novels are also quite good. But I can't stand their Enterprise-novels, despite the fact that I liked the show. They started slow and boring with Last full Measure and it's got worse with each new book.
What surprises me a bit, are the negative reactions for the Typhon-Pact-Books. Somehow it seems, that I'm the only who liked all four of them.
I enjoyed all of the Typhon-Pact books. I'm not sure why most people on here dislike them.