They're both great units. So it really becomes a price point IMO. I will tell you that if you ever break a halfshaft on the quaife, it will hurt it. So far, that hasn't hapened with a Wavetrack that I know anything about. So I can't comment on what would hapen with it.
Are you considering upgraded halfshafts?. I would highly suggest it, the pre-08 SRT ones break real easy.