I have never owned a Topre board, but speaking of the 5100C, I just happen to have this sitting here in the pile...
Just at first peel, it feels about like any other rubber dome I've tried, but I do like the compact size. I was going to use it for the little obsolete PC I use at my workbench to lookup component datasheets and such, but found a small wireless one with an integrated trackpad that seems to do the job better.
It's only my opinion, but I don't think the 5100C feels that great at all. My personal preference is for tactile-clicky, though. If this is similar to how a Topre board feels, then I guess I'll stick to Alps and Buckling Springs, lol. :-/
