depends how you play. as a bow user / summoner / (sword if they catch me), my point was not to get hit. so con was 3rd priority for me. 1) agility 2) str - to use the better armor and a nice backup sword 3) con - bit 4) int - i didnt need much more than 30 to do all the summoning i needed. bumping it up in the endgame....
im in the last bit of the game now - been bumping up con and int exclusively from lvls 39-43, but before that con was very low (30 ish) and I was just fine. and stamina was never an issue - I think i drank 3 stamina poitions the entire game.