I decided to have one of the lenses in my glasses replaced with a non-prescription plane lens, in preparation for the treatment of the second eye. This turned out to be impossible. The lens could be replaced, of course, but I could not use the glasses. I ended up with a kind of double vision that I did not encounter with the contact lens. So, unless you're wearing glasses of -2D or less, usually you will experience double vision if you simply pop an eyeglass lens out.
Some people can tolerate more of a difference.
Other difficulties I noticed were pretty much as described by the clinic. The quality of the vision in my treated eye seemed to vary throughout the day. Sometimes it seemed rather sharp, other times more fuzzy. I experienced occasional hazing, as if I had an unclean contact lens. As well, there was an occasional halo or starburst effect around lights, particularly point sources, at night.