The more hand positions you can ride with, the better. I've made and installed some homemade aerobars that give me two extra hand positions and several mount positions as well for things like, cyclecomputer, headlight, video camera, cue sheet, water bottle, etc. When I hold on to the aerobars by hands don't have to do much holding, it's my elbows that has all the pressure on the bike not the hands. Not only does it help to keep my head up better but it also takes the pressure off the hands.

Yeah, I know I'll still get numb hands when I climb since I stand up to climb most of the time and put all my weight on the hands.