The biggest gripe seems to be against the design of the trigger. Gunsmith friend #1 & #2 both think that the trigger is designed poorly due to the amount of work it can take on the rifle and trigger to get it to potentially fit some rifles. At the end of the day not a huge deal if you are prepared to get the work done to your rifle to get it to fit. It would be nice though if Tubb was a bit more upfront on the work required to get it to fit into a defiance action. It certainly takes a lot more than 3-4 passes with a file.
Gunsmith #1 has a personal preference for triggers such as the Bix 'n Andy. He feels that it is a better feeling trigger than the T7T - this is subjective and a personal preference thing.
Gunsmith #2 has had to send a couple of the triggers back for refunds. He did not specify what the issues were (nor did I press him on it), but did allude to the fact that in some cases, this trigger just won't work for certain setups. He also mentioned the fact that he knows a few people who have ordered these triggers, yet he doesn't know a single person that is still using the trigger. Again, alluding to the fact that people have moved on to other triggers. For whatever reason, I don't know.
I have a good friend who absolutely loves this trigger, and that is the reason why I got it in the first place. Obviously there are people happy with this trigger, that is apparent through this thread and the few other posts online on the T7T. The first I ever heard of any negative feedback on this trigger was from gunsmith friend #1 & #2. It's not enough to completely discourage me, but it does give me pause. Like them, I am a bit frustrated about the amount of work required to get this trigger to work so far. At the end of the day though, I'll be a happy consumer if I feel the same way about the T7T trigger as my one friend does, and if Tubb handles the replacement of my current trigger well.
In no way is this post meant to throw mud at Tubb or his products. Tubb makes stuff that works and works well, and his products are generally pretty well thought out and have a good design. Whenever I'm looking for a product, I look to see if Tubb produces it before I pursue other avenues. I have a few of his other products, and I am pretty happy with all of them (jury still out on T7T). I am going to remain optimistic about the T7T trigger, and I'm sure that I will be pleased at the end of the day. If not, there are other great 2 stage triggers available.