-They're in the business of technology copying. (So is everyone else but really a transsonic looks a generation behind the aero bandwagon)
-They're hard to sell against because at the low to midrange they put great part specs for a given price point on so-so frames and I spend a lot of time explaining why ultegra costs more from me when the upgrade, the frame, isn't as quantifiable as a groupset (industry reason to not like them much)
-their QC isn't great. At a race this weekend one split cleanly along all the carbon bonds in a crash. It didn't crack, it de-bonded at each joint, and I saw a bike that came from the factory with a bent fork and a front wheel re-dished so it fit.
All that said their best bikes are still nice, but the lower prices I wouldn't touch with a ten foot pole.