In-floor cleaning is a huge variable. IMO, the best systems are GREAT. The rest are not worth the hassle. I think I am very lucky to have what I feel is one of the best and possibly the best there is. I use it every day. It works wonderfully. So far the 1st 4 years with the system have been perfect. I generally take the heads out about once a year just to check them out. I picked up several spare heads for less than $20 each in tha last year, but I've never had to do anything to any of the heads so far, so I save my spares for the future.
A friend of mine has a Shasta pool from the 80's. You couldn't pay me to have that system in my pool. The heads are terrible contraptions, they're complicated mechanical items that jam, get stuck, wear out and break into pieces when you try to remove them. Replacements cost about $80 each, when you can find them.