OK, here it comes............ POWERFLOW ARE CR@P (imo)
Had 2 in the past and my brother is currently running one, they are what all the chavs get on the 106's and the like, they are have a certain low down boom drone, they look sh*te after about 6 months as they are stain-less steel (whatever that means)
How much are you wanting to spend and where are you based? would bluflame not do a custom back box for your car as thats where id be spending my hard earned, then youl get tails like TC's and they can tune the sound to your liking.