Not particularly.
The hitbox problems aren't fixed, possibly worse.
guns aren't particularly balanced and handle more like Black Ops than Bad Company 2
the maps are small, chokepoint infused, grenade fests (a couple exceptions, but not many)
The game was obviously rushed (buggy, like glitching PBR's under the map or Armor spec doing NOTHING because it was supposed to be removed)
The hitboxes are great in vietnam
Guns do more damage, and are overall much more balanced than in BC2.
Small maps are a real problem, but other than Vantage point and Cao San CQ they're pretty good.
The PBR bug was fixed with a serverside patch already, haven't seen any other bugs. The armour spec does work, but it still only adds 25% health, basically a difference of 1 or even 0 bullets.
Vietnam is a great expansion, much more fast paced than BC2, and it really shines on the larger maps like Phu Bai and Hastings, Hill 137 and Cao San are also pretty good. Vantage Point is good once you get past the first set of MCOMs, but it really needs to be opened up.