I tend toward 1.5 ounces, since it is still possible, at that weight, to get a good big bowl, but forego the weight. I have some bigger heavier pipes, and I like their looks, and enjoy them smoked while seated. But older teeth prompt me not to try to clench 'em and to hold them in my mouth for lighting and tamping carefully. Nothing like ancient root canals and caps to make you pay attention. I don't think I'd buy much heavier than 1.6 or 1.8 at this point. Cobs are good on that score. Pipes that are small and light and have surprisingly ample chambers are really nice -- I have a number in that category.