I'm suprised with so many posts to see so few...
I'm suprised with so many posts to see so few pictures. So proud of my new smile, I'm happy to weigh in here. I see others have posted with complaints of excruciating pain. I'm not one to downplay pain--I have an incredibly low tolerance for the stuff. I'm the girl that has to have anesthetic to have her teeth cleaned. I also will not allow my dentist to use anything but warm water in my mouth. I'm definitely sensitive.
On the worst days (days 1-2 of putting in new trays), it was at the most "uncomfortable." To combat that, I did not change trays in the mornings--I changed them in the evenings, with a little Ibuprofen (or my friend, anything with "PM" in the name). I would wake with no pain, and would only experience discomfort on the following days if I left my trays out for any longer than an hour or so.
My bottom teeth were jacked up enough that my dentist wasn't even sure at the time that I'd be an invisalign candidate without first having a tooth pulled. Of course (see pain issue above), I refused to do that. Turned out, I was a fine candidate. I had approximately 34 bottom trays to start; 18 on the top. That one problem tooth on the bottom that sits back, however, wasn't quite the way I wanted it at the end, so they made me additional refinement trays. My teeth had shifted ever so-slightly differently than they anticipated, so the last few weeks of trays weren't as effective (or so the theory goes). The only bummer was that my "speed bumps" (as I call them) had already come off, so I had to have those put back on, in addition to having new molds taken. Mind you, this was all covered in my original cost--I didn't pay extra (or if I did, it was so negligible that I don't even remember).
In the beginning, I too had lis(th)ping blunders, but they were gone within a couple of weeks. And yes, if I went without my trays for any period of time, which one shouldn't do anyway, my mouth would get irritated from the "speed bumps." In addition, there were a couple of trays that cut into my gums, but you only need trim them down with a pair of cuticle scissors or similar. It's common; it's not a defect. Finally, you don't need any special invisalign cleaner--denture cleaner works wonders (this, coming from a heavy duty coffee drinker, who broke the rules and drank coffee with her trays still in).
Total: $5300, and I was told I was at the high-end of the cost spectrum. This includes several hundred dollars for a set of trays that I lost, in addition to 2 extra sets of top retainers. The invisalign people don't keep your mold on file forever, and you should wear your retainers at night for, well, ever. These were optional costs, I should add. This also covers my lingual bar behind my bottom teeth and some final touchup work with the sandpaper--my bottom teeth have shifted so dramatically, that they're not as straight across the top as I'd like them to be. My one-time orthodontia benefit picked up $2000, so $3300 out of pocket.