I'd have to say 1501's air-powered total lift was one of the best systems I've seen in action. Simple to get on, and keeps lifting even when the power is cut.
Super idea!
I noticed many robots having trouble with getting up the ramps and staying on...oops! Anyhow... driving onto a platform then lifting it with the bot(s) seems to be the best way to go.
Just my 2 cents worth.