you're right about the holy water.
i did choose to pump agility (mostly) and strength and survival for my archer -
if you look at the 'base' numbers for my hero, they're 45,96,4,1,28,10 (str,agil,con,intel,surv,speed).
you can see i really put nothing at all into constitution, intel or speed, and though i had a perm potion boost of 70 in agility, i'd still have had a 176 agility even without the holy waters (96 base + 80 equipment).
i just never saw the reason to add any points into constitution. i've always been one whos philosophy is NOT to add to hit points, instead make yourself unhittable - you get by quite nicely with minimal hit points (besides, equipment will make up for it while you're boosting regeneration).
