The new mode in Ultra now allows us to pick whatever version of a character that we like 
So I was wondering what is the best one so far forBalrog? My friend said super was, but we don’t know completely what they have done to him in ultra.
I haven’t really kept up with the USF4 changes, as anything can be changed/unchanged at anytime. You look at Adon’s st.HK which was nerfed to a single hit, but was then reverted back to its original 2 hits in the next USF4 test build.
If you exclude USF4 which is still a work-in-progress, the scariest version of Balrog was probably in vanilla SF4. If you look at the Balrog frame data from SF4 (wiki.shoryuken.com/Balrog_(SFIV)) and compare it to SSF4 (wiki.shoryuken.com/Super_Street_Fighter_IV/Balrog), not a great deal really changed apart from the damage reduction every character received in the transition from SF4 to SSF4.
IMO, vanilla is probably the best version of Balrog. He got very few changes, aside from headbutt being nerfed (in damage and recovery) and j.hp. There’s only a couple of other small changes that I feel no-one really misses/notices.
I think the bigger issue is that older versions of Balrog don’t get delayed wakeup. So it’s a bit difficult to say Vanilla would be better. In USF, system changes put him up the tier list easy. But vanilla Balrog’s far st.lp and j.hp are definitely much better. Like delusional11 said, his frame data for the most part is in-tact between versions.
I like AE (current) balrog and his iteration of U2, but i’m definitely in the minority. I’d say Vanilla Balrog, and then current Balrog are his strongest incarnations in SF4.
Vanilla rog.
Higher damage ultra 1, 160 damage HP headbutt, 110 damage on all jumping heavy attacks, huge hitbox on jump HP, safer headbutt that can be used to navigate fireballs and maintain charge, far standing LP that hit tall characters while they crouched (Abel, Rog, gief, Sagat), more damage on standing Mp (close and far)
Vanilla Balrog is best.
160 damage hp headbutt, standing lp hitbox bigger, headbutt on block safer, jumping hp better hitbox. Clearly the best version.
Ultra Balrog looks like really pointless changes. I hop edition select will be available at the arcade cabinets, as I’ll be picking vanilla Rog, as I’m sure the Sagat/Ryu/Akuma players will be picking their vanilla characters too.