Harden is 3/4" taller, and has a standing reach 3.5 inches higher. Beal's standing vert and max vert are both two inches higher than Harden's, and his lane agility is better by a smidge, although Harden has a surprisingly fast 3/4 court sprint (up there with Wall and Booker!!!).
Beal is clearly more agile and can jump higher, although Harden's height advantage compensates for that somewhat. Harden's measurables are the minimum required athletic talent to be an NBA player but otherwise kind of meh. His shooting percentages are kind of meh too -- better than Brad, who despite shooting 43% from three shoots a MISERABLE 41.4% from the field -- while Harden shoots a pedestrian 44.6% from the field and 32.9% from three.
So why is Harden a max player? He earns an amazing 8.8 free throw attempts per game. It's not just that Harden is pretty good at drawing fouls -- that is his elite skill.
In other words, without "cheating" (or to be nicer, drawing fouls at an elite rate) Harden has average athletic skills and average shooting skills. Drawing a foul is his go-to move.
I don't know where I'm going with this -- clearly Harden is not a cheating flopper, he just has a skill that he uses to his advantage, annoying as it is to be the victim of it. It doesn't feel like a legit skill because he's using the refs to beat you rather than his own innate athletic skill and/or talent, although the nerd in me likes how he uses his wits to overcome an otherwise average NBA toolset.
It does explain why he chose to flop with the game on the line the other night. The refs fell for it and his team won, so all's fair in love and war, I guess.