I did Knapsack col, from Peak lake, in August of 2005.
I had no mountaineering equipment. Didn't need it. I did have a light pack (18 lbs. for 4.5 days) and a good pair of shoes.
At that time, the descent to Titcomb Basin was mainly on snow with a scree/talus section before the Basin floor. I hit the snow during a warm mid-afternoon sun. My feet were very wet by the time I got to the Basin floor. Maybe 75% of the descent was on snow. That's a ball park figure.
The valley above Peak lake is scenic, but the last 500' or so to the col is a steep grovel. I guess you need to do it once, but I wouldn't do it again. That's my view.