We can sit here and argue all day about height, weight, etc. Who is to say Heath actually weighs what he claims? 
The bottom line is that pound for pound Dex is bigger, denser, and more conditioned than Heath has ever been or will be this year. Dex is proven AC champ whereas Heath is not. My money is on Dex.
I can attest I saw Phil step on a scale at Golds Gym when he was in Phoenix last October. Saw with my own eyes, 267 lbs and lean!
Dex was here last July for a guest posing gig and he claimed he weighed 230 lbs. at that time. Not disputing it, just that these guys or all bodybuilders for that matter can add 5-10 imaginary pounds.
Ironman, I think, weighs the contestants so will be solved in a couple weeks what Phil comes in at.
Proven at the AC or not, Dex had to win for the first time, why can't Phil? Like the great Chris Berman always says, "that is why they play the game"...all this is a mute point until we see them side by side and not in a post on the web!