It started doubleclicking after 3-4 weeks of use. I have an average size 7 foot. The second pair was much better but not sure how well they will hold up over time. My only criticism is that the nylon tread on the bottom that is applied to the rubber sole tends to wear quickly. In the morning, they seem ever-so-slightly damp from the previous day. Very soft and comfortable on the feet, with a cushy sole (like memory foam). With all that said, I was able to get this working ,Not recommended as a simple plug and play replacement for the 500X. Leider steht im Forum nur der Monat und der Tag, an dem das Profil hochgeladen wurde und auch die ?Nach Datum sortieren?-Funktion gibt keinen Aufschluss über die Aktualität der Profile. I was surprised at how light and flimsy it was when I got it today. I bought in black and in white and am about to order a few more colors now that I have successfully test driven two pair.