An epic hour lasting 2v2 game in DBP environment.
I cannot measure all changes per se because do not feel competent enough to do so. But the game played very well for both sides and the balance felt very good for me. Actually the players were deciding the outcome of the game, not a One Click Wonder Abilities and Axis Wunderwaffe.
About singular units:
Jackson
This unit is in a golden spot for me right now, see no reason to buff/nerf it any further.
Elephant
Right now a very niche unit because it only serves as a tank counter, yet USF only has paper armour so it is not very needed. Maybe against heavy tanks or as a counterpick to ISU152 doctrines. Otherwise sticking with Stugs is adviced.
Brummbaar
Seems a bit OP now with tier4 changes. I would suggest to decrease its armor to make it more counterable by medium tanks (so you dont need Jackson to counter it) or decrease its aoe a bit (buff mgs to compesate) so it is not so squadwipey 
The Meta
I think that the tank meta will shift from medium tanks and generalist/specialist heavy tanks into specialist AI tanks (like Scott or Brumbaar) and dedicated tank destroyers.
The reason behind this is that medium tanks are hardcountered by dedicated tank destroyers and so are the heavy generalist tanks. Yet they cannot bleed infantry as much as dedicated AI tanks.
Dedicated AI tanks are strong enough to bleed enemy army and then pull back from enemys TDs. Tank destroyers are now strong enough to hold the line against each other and hardcounter medium tanks so dedicated AI tanks which are nimble enough to escape or strong enough to take a severe beating seemed like a better option. At least in this scenario.
Overall the unchanged cheese remained the same.
Smith, I think you should watch this one, because it is a good match that pretty much shows you how the DBP 2v2 meta on open maps will look like
You forget that the brumbar has no turrent, is slow and has not the range from a scott...
so when it need to stay at the front and turns slowly the chassie...it must have more armor/ HP...else its usless...
Jackson is not in the golden spot...its in the top spot...its little bit to much to have a fats TD with turrent, good Dmg, high range, very good pene, and now high HP...
2 of them...and no armor have no chance to hold the front