if you want a great sounding exhaust, go with msa's twice pipes setup. sounds amazing imo. it's loud but not obnoxious. again...my opinion lol. i've gone on 2 hour canyon runs windows down and didn't get annoyed at all. also gave my Z some great higher rpm pickup. really screams now
but, if you're not into that, go with the dynomax. best deal in my mind and if i didn't get the twice pipes, it was the dynomax.