I saw a set of Eurotrax this weekend. If I could wave my magic wand, I would turn my cat trax into a pair of Eurotrax. The look like they're much more user friendly to assemble. No drilling involved, and the width of the cradles is easily adjustable with a knob. Best of all, you can easily break them down for transport.
Follow Rick's advice, and check 'em out at the store!
Tim J.