I have only climbed the South Coulior and I think a belay would be a good idea if you have less experienced climbers. It is pretty consistently steep and there is a midsection rollover where you can not see the bottom when you look down from the very top. When I climbed it there were NOLS groups who were all belaying from the rocks on the side. The snow had softened mostly, but the bulge in the middle stayed firm, and this was in August 1998. It is steep enough to be intimidating, but a very direct way to the top. When I was there the glacier at the bottom had reliable tracks on it and no obvious crevasses, you might want to try to find out conditions from one of the local guide services. Good luck and enjoy.