I am running a Raptor Turbo muffler on my DD right now. I cut the stock exhaust at the old muffler and welded on the new 2 1/4" muffler. Sounds great. Kinda gets to your head on longer trips though. I still need to run a tail pipe. Baxters has them in stock.
This same muffler sounded great with a complete exhaust system (minus cat) on my other toyota. not annoying at all.
I am also not a fan of Flowmaster. Yes, they are built well (welded) but they dont sound so great on toyotas.