I have tried the Two Bros and Ztechnik. Both were too loud for me. I like a good sound, but on long rides it got on my nerves. The Two Bros was even worse.
I have a Laser DuoTech that I like. It has two inserts, one sporting, one a little quiter. The sporty one has a very nice sound. As to performance, it is hard to tell unless you dyno it, which I did not do. The Laser is easy to mount, takes 10 - 15 minutes to swap if you want the stock can for a while. Use a cat eliminator (Sebring) as well. If you put an exhaust on, you will probably get some popping on decel. unless you put a chip in. I have the BBPower chip, it works well.