I've had them for a few years. I've always used the disposable ones, which (a) being floppy gel things are supposedly more comfortable than the glass sort, and (b) don't need you to set up a chemistry lab in your bathroom.
My optician (Specsavers) wouldn't let me start using them until I'd proved I could get them in and out unassisted. Most people manage this on their first appointment, but I "failed" (that blink reflex thing) on my first appointment, and had to come back for a second. A friend of mine had to come back every day for a week before she finally "passed", but we both use them like second nature now. At first, I used to allow 20 minutes in front of a specially purchased tabletop mirror for getting them in/out, in a battle of nerve between finger and eyelids. Now it takes seconds, but I still need the mirror.
For the first few weeks, after I'd had them in for upwards of 4 hours or so it started feeling a bit odd (slightly scratchy/sticky, but not painful at all), but then I got used to them and could have them in all day without noticing.
But it does feel brilliant when you start using them - like your eyes have been miraculously restored! Well worth it.