I personally don't have a problem with Intense. After reading some stories on the internet i am going to have to do a lot of research when it comes to deciding between the XP or S1X cam though.
I personally went with the S1X because ive seen that the xp bleeds off boost and to be perfectly honest I chose intense over zzp because of my experience with them.
Now when i had the cam in my engine it made great power, the ONLY thing i didnt like with it was that it seemed to have shifted the powerband up a little and when the engine would drop into 4th at 40 it seemed like it didnt like it a little. but boy did it like it up top (trans hated it tho lol)