XT and XTR both shift 2 gears on the upshift (small paddle) if you push with your thumb, if you pull with your index finger they both shift one gear.
I’ve had XTR and XT. XT is more positive in action, much more positive, which I prefer. XTR is lighter action and a bit more vague.
Carbon lever on XTR is nice, but makes no difference when wearing gloves apart from being a little slippery compared to XT.
Both work equally as well as each other, but I think XT is better, depends what sort of shift feel you like? XT also has had more time to evolve from XTR and iron out flaws.
I currently run XT and sold all my XTR rather than swap it to my current bike.