So when I'm around 5-6k rpm and give a quick roll-on the throttle, it feels like the clutch slips a little and then grabs and goes. Or it's like the ECM is slow to respond to the throttle change; like it's getting more air and fuel, but the timing isn't changing immediately so there's a short delay (1/2 - 1 sec) and then you feel it kind of kick in and really take off. Usually it's very noticeable kick, sometimes not so much.

It's been doing this since day one, I thought it was normal, but talking to a couple other guys it doesn't appear so. Solenoid cable is removed, cams are zip-tied together.

My TC was off. I put the trans in neutral and turned TC to 5, then back to off, thinking it might be something there...no change.
I did a TPS reset. No change.
My next thought was to disconnect the vac line to the clutch (cap both hose and port), maybe it's holding some vacuum that's keeping the clutch from fully engaging under immediate load?