I have to agree, that Toro clock and the valves I have had good luck with, but all the heads are junk. The super 8 and mini 8 where both to be huge game changers when they came out, but they are merely no more than junk, and as you experience the worst part of them is a weak spring and stiff seal causing them to stick. All in all the 570 is a decent spray but to get a good retracting you need to go with a PRX. If you want to keep the site with one manufacture I would go RainBird. On new installs that is all I use and have used, other than a Irritrol RS. RainBird 1800 series SAM's are excellent at retracting and hold adjustment very well, for the larger areas 5004's are great but you could step up to a 5500 series. 5500's are priced higher but are a truly commercial grade head. They are a pain to adjust at first until you get the hang of the left and right adjustment but they are a very rugged head. One last point to go along with everyone else is proper installation techniques and practices. From glue joints done properly to setting heads at the proper height and compacting around them as to the dont settle in a years time will do leaps and bounds for any system no matter what product used. Good luck and hopefully you can turn your nightmare into a joy to work on.
CIC, CLIA, EPA WaterSense Partner. And working on my CID