I agree with 1 1/2" minimum, when I can catch the butcher cutting, I have him cut them at 2".
I don't have a very functional charcoal grill set up so I have to go with the gasser. The "new" gasser doesn't heat up like the old cheapy with lava rocks so I do the best I can by preheating with a sheet of HD foil over the cooking grates. I cook over the hottest spots for about 90 sec per side twice to get the nice "crosshatch grillmarks" then kill all the heat except what's heating the cherry and/or hickory chunks.
Steaks go indirect with the smoke until they feel like med-rare when given the finger.
Rest for 5-7 mins while I prep my baked potato and dress my salad.
Then I eat tooo dammed much, then I sit on my ass tooo much and grin like Buddah