I've used the Travel Trac's from Performance over 70 times in the past 9 months and they are holding up fine. Doesn't seem like there is much that could go wrong with them (except for maybe the bearings wearing out some day). They fold up and can be put away when not in use. They're reasonably quiet so I can still watch a movie or television (with the volume up a bit). I can't speak for the Kreitlers but I'm glad I saved a couple hundred and bought the Travel Trac's.