Very interesting thread.

P.E.H. , I've noticed a rather slow acceleration response in my SDL too and have chalked it up to a heavy vehicle, low hp, and highway gearing. My 0-60 is decent (about 12 secs) but I almost always give it 90% throttle off the line (once it's warmed up) and experience no grey smoke unless I go 100% throttle. The only way I can "light-up" the tires is if I'm going around a sharp turn and floor it - when it's wet!

Sounds like I have a few items to check too.