I did ask Richard's opinion about the sled and he was right....it wasn't easy going up the lower part of the North Fork.
Basically we had small internal frame backpacks that were not big enough to carry all of our stuff. And in a way we wanted to test out the sled idea.
We tied about 3 sleeping bags and some pads on the sled. Going up the road (covered with snow) was relatively easy. Much of the lower trail was not a problem either.
Once we entered the North Fork (mostly above the inviting canyon to the Left - below the Ebersbacher ledges) it became more difficult.
http://outdoors.webshots.com/photo/2719523800061435028YpYHBr There is no trail there and it is not in any way horizontally level. It worked best to have a rope in front and one behind. Otherwise the sled slid sideways one way or the other. Often it flipped over and our stuff fell out a few times. It was kind of a pain at times.
Once we got to Lower Boy Scout Lake the sled was easier to use. It is more horizontally level from there on up. Going up the slabs between Lower & Upper Boy Scout Lake the sled also came in handy.
Although we did not go higher then that it would have worked through the Morraine field above Upper Boy Scout Lake, as long as one picked a route where you were not walking across a hill sideways.