I've got a '02 2500 HD Duramax/Allison Crew 4x4 short box. No lift, not even "cranking" the bars, and I run 33" Bridgestone ATs. Taller tires were somewhat for looks (as opposed to the skateboard looking stock tires) but also for improved clearance and footprint since I am sometimes "off road" in it (camp sites, washed out dirt roads, etc.). Honestly, a little lift probably wouldn't hurt much, but it *will* make a difference. How could a higher CoG and more unsprung mass plus leverage against the suspension and brakes not make a difference? The more you lift and bigger the tire, the worse the consequences. If I “get into trouble” towing, I want every advantage I can get. Not worth it to me for an IFS lift. I don't "wheel" my tow rig and lifting it is just a lot more expense and stress on lots of parts (specifically the IFS).
And honestly, I think most of the IFS lifts look sorta silly anyway. Once in a while you see one that gets moderate use, but 99% of them are pure posers. All that money to make something weaker, slower, drives worse, less comfortable, and add more maintenance… Compromises for function that matters more to a person is one thing, but giving up that much for looks I simply never understood. Just my opinion.