I have seen it work just fine and it can end up saving you some money. Pay attention to insulation, pipe insulation, duct insulation. Also cover any insulation with either plywood or wind barrier as moving air can rob 1/2 the insulating properties of batt insulation. A detail I have seen that looks good is to cover the posts, piers and the spaces between them, to slightly below grade with 1/2" cement backer board with a little tape and parging and it ends up looking just like a regular foundation.