Some people like them, others have had nothing but trouble with them. But personally, I would NEVER install an in-floor cleaning system given the myriad of things that can go wrong with them plus, they are energy hogs and significantly reduce the efficiency of the pump and plumbing system.
I would have to respectfully disagree.
Myriad of things that can go wrong - These systems are actually very simple. A single 2.5 inch return pipe feeds a distribution valve which alternates the zones within the pool. The plumbing is typically encased in gunite and feeds rotating heads. These heads have no moving parts.
Some people will say that having all that plumbing is the floor is risky, etc, what if its fails, blah blah blah. But the facts are that this RARELY ever happens. Not to mention, many many builders are encasing return plumbing in the gunite anyway
The heads, distribution valve, and leaf canister are all covered by a lifetime warranty. The heads can be changed easily - a 1 minute procedure. If one were to fail, just call A&A and they overnight a new head. Simple.
Now, as far as in floors being an energy hog. Also, not true. The newer systems use 3 inch suction side plumbing and 2.5 inch plumbing on the return to the water distribution valve. The A&A system (the one I own) uses a new style of head called G4V. Essentially, it is a venturi style head which allows more flow and lower GPM. I run my system for 3 hours per day at 2800 RPM. With an intelliflo pump, these systems are actually fairly efficient. Much more so than polaris suction side cleaners with the independent pump. Obviously, robots are best in terms of energy, but they have there own sets of cons.
As far as efficiency of the plumbing system - I would say its the most efficient plumbing system around. Most in floor systems also make use of venturi style skimmers, meaning they receive all of their suction from a return (no active suction from the pump required). This allows 100% suction power to be allocated to the drain for maximum debris removal. I have personally tested many pools and I can tell you at 1500 RPM, the venturi skimmers are MUCH more effective that typical skimmers at low RPMs.
And of course, the benefits of increased circulation and more efficient heating should not go unmentioned.
In my opinion, hands down, in floor is superior.