I had several sets of Guide R and RS levers develop up/down lever flop, where the lever has a considerable amount of vertical play. You could grab the lever and push it up/down a fair bit, it eventually got bad enough that I could feel it while riding. I had a similar experience with Shimano brakes, although to a lesser degree.
I can't say if the Code Rs suffer from the same problem, the lever is a bit larger, so maybe the bushing in there wears better than the Guides. I just typically prefer bearings in the lever to avoid this becoming an issue.