I'm planning to hit up the Swiss Arete on Sill over the weekend. How much of the approach to the route and descent are on snow? I'm guessing that mountain boots are the recommended footwear, but what about ice axe/crampons? Any advice from people who've done it at this time of year?

I was up there 3 weeks ago. I'd guess you could get to Gayley camp without incountering much snow at all. From there a pair of light boots with crampons will work. Last year I used a pair of high top GTX approach shoes for the snow travel and the first half of the route. They were just fine.