I am 5'9, never any less than 5'8.5 by the end of the day, and I can verify the heights of the pros. Also, if any getbiggers are around, I don't mind verifying my height.

Jay looks around my height, maybe a bit shorter, but no less than a full 5'8 and maybe closer to the 5'8.5-5'9 claimed. Ronnie looks no less than 5'10 and probably as tall as 5'10.5. PJ Braun looked to be at least 5'10 but he was wearing thick heals. Dennis Wolf is 6'0. Toney Freeman is the 6'2 claimed. Ben Pakulski and Fouad Abiad are both at least my height, but no more than an inch taller so I would say they are the 5'10 claimed, even if they are both weak 5'10. I would say Dennis James is the 5'8 he claimed. Most pros are around the height that they claimed. Branch Warren may be 5'6 rather than 5'7 and Shawn Ray might be 5'6.5 rather than 5'7.5. Frank McGrath looks to be 5'11 even.
Ron Avidan is 6'1-6'2 with crap posture. 
But seriously, he looks to be that height and his posture is actually better than I remember it from before. Ron is looking well so good for him. Most pros are more or less the height they claimed. Oddly enough, Dennis Wolf is an exception to this because he has claimed he is 5'11. I think he is just used to the metric system in Germany and got the conversion wrong.