I also have a first-generation model. Not only does it often skip, but it's slippery! Sometimes when I'm doing a lot of switching, I'll use a rubber thumb cover from an office supply store (the kind you would use to turn pages or count money.) IMO the ergonomics of the thumbwheel are dreadful. Hard use of the "push-to-enter" feature can eventually cause the thumbwheel to crack. And servicing these remotes is a headache best left to experts. 
Several years ago begged Mike Wolf to make a new / redesigned remote, to no avail. It's also a shame the DCS Commander has a limited feature set and doesn't operate the older Proto-2 locos, because I don't always need walk-around control, and like the tactile feel of that controller MUCH better!
I think the company's strategy is to encourage users to control their trains from touch screen devices. If you have PS3 locos, you could also control them with DCC; some of the 3rd party DCC hand-helds have better ergonomics than the DCS remote.
