I've had both the dynamax super turbo's and the magnaflow. Dynamax was alot quieter (could barely hear it) but they have a more restrictive design. I'd say go for the magnaflow...it's straight through, stainless steel, and sounds great. If you want one I have one for sale with 2.5" inlet and outlet, i used it about 2 weeks

 

Looks like I'm going with a Magnaflow...and a evo fmic.

 

Well if you ever need a really cheap one, I used 2 summit 3" resonators - they're basicly spiral-louverd glass-packs. A 24" and 18" with nothing else besides flex pipe, 3" I fabbed, and turbo. Sounds great, no rasp at any rpm, quiet when idling, sounds much more like an evo at WOT than a sohc.