I'll start out by saying that by most accounts the Outback-II is a good can - not as good as the Warlock or Spectre, but good.
I have yet to find anyone that recommends a Trinity over a Trident. I am aware that the Trinity is discontinued, but when I started looking for a multiple mount can those were the options.
There is compelling evidence that they steal designs from other people, while accusing others of the same. The baffle stack in the T2 for example is curiously similar to the stack designed by user green0 over on the silencertalk forums. The inertia device for their new Multimount was quite obviously a direct ripoff of the booster from the AAC Evo. The parts of the booster are even interchangeable.
http://www.silencertalk.com/forum/viewtopic.php?t=22033
There's the issue of them trying to get ATF to not allow manufacturers to fix cans that they did not make. AAC has on several occasions rebuilt crappy Gemtech cans into something better, and that is bad for Gemtech's business. The effect of their bitchiness could have been that owners would have to pay another transfer tax to have a can rebuilt - thankfully, that has not happened.
The Gemtech G5 failed the military torture test that 6 of AAC's cans passed. The G5 failed miserably, partially due to key components being held together with roll pins instead of being welded. The thing literally fell apart.
http://www.silencertalk.com/forum/viewtopic.php?t=10473
They claim that it passed the test on a different occasion and many were sent out to the military. If that's true, then either their build quality is inconsistent or they intentionally sell inferior products to non military customers.
Yes, I'm aware that silencertalk.com is owned by an AAC employee. Even so, there's just too much evidence of shadiness for me. And when dozens of board members, several shooting buddies, and two dealers tell me I'd be better off with a can from a different company - well, that's enough for me.