Using keys does NOT improve the ride. They let you crank higher, but you can only go so high before you will be constantly riding on the bumpstops. It's this that ruins the ride. You won't break your bars by cranking. Some people claim increased wear on front end parts when cranked, but this has not been a problem in my case. With stock keys you can easily get 2"
I have used blocks or leaves to raise the rear. Blocks keep the ride the same as stock. an AAL will make for a stiffer rear suspension, but will aid in heavy hauling if you do a lot of that.
Bill