Why aren't the WH-R500s good enough? I understand heavier people have problems with these wheels, but that would hold true with any low spoke count wheels. If you're looking to shed weight, then to what end? Is the bike used to race? If its not then buying nice wheels to shave weight is a waste, IMHO.

I'd say, if you're at normal weight for your height, then check the wheels over: make sure the cones aren't over-tightened, re-grease the bearings, and ensure the wheels are tension-balanced and true.