I haven't used their design system, but I do have Rainbird sprinklers and they work well. Except for the ones I busted up with the mower. I recommend putting sprinkler donuts around each one to avoid that problem.
My only complaint with the Rainbird sprinklers themselves is that adjusting them to spray in the right direction is difficult.
As for the right time to install a sprinkler system, that depends on where you live. Here in Florida, winter is probably better as stuff grows more slowly which makes it a little easier to dig. But if you live somewhere where winter means frozen and/or snow-covered ground, then spring or summer is probably better.