There is an ongoing thread regarding a Class A rig purchased by a gentleman who almost immediately experienced a severe malfunction that damaged the slide and wall. The Schwinny was his first targeted culprit but I believe it was determined that manufacturer error caused the problem. Basically Schwinny work great under ideal conditions but get messed up easily when things are off. In the above case the slide was mounted crooked I believe. If it were me buying the rig I would just cycle the slides in and out an obnoxious amount of times. Then see if there was any binding or grinding.