I have the Lsxr102 intake with matching tb. I hope that the self tuning capabilities of the Holley xmax will help with this. Are you guys saying that it won't or if you are tuning stock computer that it's harder?
I'm using a Megasquirt and the only issue I have is at light throttle tip in. If on the highway and I ease into the throttle, then I have no issue. If I stab it at highway speeds, then no issue. The issue comes with an increase TPS of 2-5% in a 1/2 - 1 second. It might go a little lean or might get a little too rich. The same goes when taking off from a stop. The MS will allow for accel enrichments based on both TPS and MAP changes or a blend of both - I've spent more time tuning this to an acceptable level than anything else. I've had the ecm set from 0 to 100% EGO correction with the same result. I'm happy with it, but it's not as smooth as a smaller throttle body will allow.
Keep in mind that this isn't just a 4.8 or 5.3 thing, I have 420ci's and it's an issue. The local dyno tuner confirmed the issue - he is a both a friend and sharp tuner, and his response is 'live with it or swap TBs'.
As I mentioned previously, I'd put on a 92mm if I were to do it again. My boosted build is different than a NA build in some regards, but here's the importance of a 102mm vs. 92mm - my motor doesn't care if the throttle is at 70% or 100% - it makes the same power once the boost is all in - and TPS % has no bearing on boost building over 50% TPS. So I don't believe the smaller TB would have any effect, positive or negative, on power production, but it would be more tuneable for daily driving.