I think that the best made and the best flowing "x" out there is the Bassani....its a work of art at the x section..........smooth and large enough to scavenge out each side. Though I have the Corsa Indy's (and LOVE the sound at WOT with them), I still think that the Bassani is the best X. Look at the "x" sections of the ones you are considering, and see which ones you think flow the best.
As a suggestion, if you can find someone in your area with the complete system you are considering, do a couple of things....
1. Go up a hill in your area with the car under load at about 1800 to 2000 rpm. This will test for low RPM resonance.
2. Cruise at 60 to 70 MPH and do a slight throttle roll on, without downshifting (for the same reason above).
3. Find a tunnel in your area, roll the windows down, take the top down or off if so equipped, and do a full throttle blast in first gear. This is the only way you are going to hear what it sounds like WOT...........
