The main issue is the paranoia of sleeping with them on and knowing that if you rub your eyes, it's possible for them to break and cause serious damage. I'm not sure how likely it is, but was a recurring worry and source of nightmares.
It's also something you have to do every day, otherwise it takes a few weeks for your eyes to return to the normal shape.
I experienced some undesirable effects daily: vision sharpness was perfect in the morning, but would noticeably regress starting around 3pm; I saw halos at night; and the combination of progressively more blurry vision and halos made my night vision really suck. I wasn't comfortable driving at night, and seeing stars in the sky was impossible (maybe sounds silly, but I found that to be a quality-of-life issue). Also, I think the area that could be treated was narrower than my field of vision, similar to how glasses treat a narrower field than regular contact lenses.
Turns out my pupils naturally dilate far more than the average person's (so the halos were partially treatable with brimonidine daily), and my cornea either isn't thick enough or reshapes itself too quickly -- or both, can't remember exactly. Whatever it was, I remember my doctor saying that I would probably experience similar undesirable side effects were I to get Lasik.
Most people here would probably be better off with ortho-k than with LASIK, so long as their myopia isn't severe.