I'm 52 years old and began my invisalign treatment in May '11. I'm on tray 17 and I'm very happy with my progress so far. I tend to clench my teeth at the front, which actually has been helpful in moving along at about 10-11 days a tray. My orthodontist checked at my last visit, saying I'm not having any splaying of my back molars, so all is well. I began at the second tray with my 5 attachments, so I've had the "snap-on" experience from the start. Mostly hate it when I occasionally catch my lip while taking them in or out. Otherwize, it's been fine. The pressure and tenderness go away within a couple of days per tray. I see it as a pretty inoucuous way to overcome my lifelong desire for straight teeth! Another 15 trays to go and I'm set for the rest of my life! I'll load some pictures soon. Updated on 16 Oct 2013: So it has been a while... I may seem weird, but I didn't mind the process at all. I never thought of the pressure or tenderness of the teeth moving as "pain". I followed the instruction of brushing my teeth after eating EVERY time, and man, did I have great results with my oral health because of it. Routine cleanings were a snap and my gum and bone health improved to A+ ratings. So, what happened? I had trouble with my lower eye teeth not turning, which is the only real problem I had with Invisalign. This caused my Orthodontist to reorder the last half of the program to double the amount of trays/time. This was fine with me, and I would change my trays only when they were "loosening" as the teeth conformed. Then, when we had gone as far as we could with it, he recommended the metal for my lower eye teeth, to get them perfectly aligned. This was part of the cost, and I was up for it. That partial in metal was for tour more months. Now, I am so very happy with my smile!! Doing all this saved at least two teeth, that had a tartar secret up under my gumline, that could have cost me losing them. I am not whistling on my "s" anymore, and I feel I gained a lot of self esteem about my appearance.