reducing exhaust drone

I am leaning towards the resonator way, but the price for the Flowmaster 15150s is $160.00 each, and needing 2 is over $300.00, found Vibrant 1141 which is about the same size and spec as the Flowmaster units, and just also found that Summit has there own # sum 639436 for only $70.00 each, has anyone used any of these to give feed back on ??