Can't remember exactly how long I've had them - a couple of months, I suppose. I wear them for about 7 hours each night, they're dead comfy, just slightly bigger than gas permeables (they're rigid gas permeable lenses). You put them in before you go to bed (can read in them for a bit first if you like), then wake up with 20/20 vision.
Because I wore rigid gas permeables to correct my sight anyway, I had to leave my lenses out for a month so that my eyes went back to normal - any contact lens changes the shape of your cornea to a certain extent. My eyesight actually got worse - my eyes had been slightly corrected by my ordinary lenses anyway.
My eyes were about -5 and -4.5 and the -5 had 1.73 astigmatism too. But they're 20/20 now My eyes went to something like -2.5 and -1.25 after the first day (am sure the exact figures are on MN somewhere - I've talked about it before!), so I wore soft lenses that day, but the next day, I had good enough for driving eyesight, the day after it was 20/20.
For some people, it doesn't work. I have particularly malleable corneas - mine is the worst prescription my optician's worked on and he was surprised to get such a good result.