The RDX500 has gained an enthusiastic following, based on its touch and arm-friendly flex, although I have seen it described as "mushy". Its a narrow 18mm beam , heavyish (12.3oz) 98 sq in headlight (8 pts) stick, so its specs fall easily into the "players racquet" camp.
Mine came strung with Pro Supex 17g, which is a soft low-powered string anyway, amplifying the RDX's prime characteristics, to make it TOO soft and low-powered. I had also put this string into my Wilson Hammer 6.2, and wasn't impressed with how it went in that, either. With both , I have plenty of control, but struggle to exert any sort of pressure on my opponent.
I'll try it with something livelier some time and see if I agree with its many fans.
UPDATE - November 2015
Well it's been a while coming, but I've come back to the RDX; and am I glad I did.
I had been using my 'ol faithful ProStaff 5.0's up until now, but lets face it, they are brutally stiff and consequently so hard on the arm; I tried flirting with the Wilson Blade 98 to avoid the punishment, but they are so different to the PS5 I never felt comfortable;
In desperation I turned to the RDX as a stick with a reputation for being a bit kinder to the arm, and replaced the awful Pro Supex poly with a hybrid Wilson Extreme 17 / Polystar 17 mix, strung 57/54, that I was using on my PS5s;
Wow, what a difference; gone was the mushiness, ping went the volleys, decent power was back, it felt perfect. Now I know why this stick has so many fans, it is a true all-rounder.