I've never ridden pontoons, but hellbents are okay on hardpack. They're very soft and tend to chatter through high speed turns in any snow that's less than an inch deep (ie. all groomers). The 08 seths are much more stable on piste, and the 07 seths are even more stable. If there's not more than a foot or two of powder, seths work fine for me. But in deep pow, hellbents are fun.