I currently shoot the SQ2 and it is one sweeeeeet shootin bow. Very quiet, no recoil, and fast yeet tame-able. At first i loved it, then i heted it, then i loived it agian, then i hated it, and now i love it. But all those love hate periods happened over a two week period. If you have a problem of tourquing the handle, its not for you.
I talked to the pro shiop owner and he said the ultra 2 is a nice bow, but like PA said, the low brac hieght makes it tough. A friend of mine had a firestorm and the thing blew up on him, dont know if it was jus that bow or what. I dont know about any of the others. But as you probably figured out, i love the SQ2. Good luck shoippin