I ran test pipes with a stock CBE and loved it, very nice, especially down shifting on the limit, some rasp though at 2800, I then added an INVIDIA Gemini, it was very loud but very deep and sounded great, adding the CBE did open up more power over just test pipes.
Currently just on HFC's and not run it yet as no time, it did sound deeper at idle though.
Heres some vids of test pipes with ICBE.
Kellys 370Z :: MVI_4454.flv video by kastley85891 - Photobucket
Kellys 370Z :: MVI_4464.flv video by kastley85891 - Photobucket