My trays were complete after about 9 months. The effect on the appearance of my teeth was dramatic. I have two major complaints though.
First, many of the trays came with sharp rough edges that would cut or rub my tongue raw. When I complained to the dentist he said I could file them smooth with a chain saw file, which is in fact what I had to do. It just doesn't seem to me that I should have to do that for something which costs so much.
Secondly, a year after completion of the treatment I find I still have to wear my retainer tray almost 24/7 or my teeth start to move too much. I expected by this time to be able to wear it at night only.
Also, delivery of the retainer trays has not been smooth. Too many complications and phone calls required for something which should be automatic. Also one of my goals in having my teeth straightened was to make them easier to clean. The permanent retainer bar fixed to my lower teeth has made them much harder to floss around.