I have been using kneesavers for 5-6 years. I have had no mechanical problems with them. They are well machined and hold up. I have just the left kneesaver on my commuter bike and our tandem, with Look FQV pedals. I have both kneesavers on my road bike, with speedplay frog pedals.

I have wide hips, and I have a below knee artificial leg. I cannot use clipless pedals without a kneesaver on the artificial leg. My prosthesis would hit the bike frame, otherwise. My prosthetic alignment is very non-textbook.

Kneesavers are not compatible with some crank brothers pedals. The standard pedal wrench does not work on the kneesaver - it needs a slightly larger wrench. I just use an adjustable wrench.

The only thing I disliked about ordering from SCOR was the sheaf of advertising about nutritional products of questionable value that came with the pedal adapters.