Im 6'1" and went with 501's I like the feel. If I had to do it over again I would have done the 500's. The 501's look good on my Train but the risers looked real long. I added a fork bag on the bars to fix the look...Now I love the look.
I got the 501's also for my 02 FXST and I agree that the 500 may look a "little" better since they are 1 in shorter in rise but also 1 in shorter in reach...I am 5'10" too...Mine are very confortable and your seat can make a diff in reach. But whatever one you get make sure you get the polyeurathane damper kit cause your stock rubber bushings wont hold up more than a few weeks.