Ha! Too funny, obviously I don't eat burgers. It doesn't matter though, I can eat 30lbs of tuna in three days and still not gain an ounce. Just to check, I jumped on the scale: 169 just now. My BMI has been around 6-8% my entire life.
Anyway, more testament to how warm a Drylock is :P
The technology between the two isn't the same, yet. Right now, Xcel has that new material they are making their top end suits with, that Rip Curl only offers in the 3/2 and 4/3 F Bombs. I would imagine that the 5/4 F Bomb will have that new type of neoprene soon. So currently, the top of the line XCel is more advanced than the 5/4 F Bomb.
With that said, I surfed a 5/4 F Bomb last winter, and was never cold (North Jersey). Switched to an E Bomb this year (F Bomb was a large, and too small, traded a guy with an XL E Bomb who needed a large), and still am yet to be cold this winter.
Long story short, wetsuit technology these days is insane. Get the suit that fits your budget and fits you properly. You can't go wrong with either.