I currently have a 7850 but I am looking to upgrade to an r9 280x or 290 ... It's still a great card, I am sure it will run both games fine.
I currently play bf4 at 100-150 fps on lowest settings in bf4 multiplayer. Since I have a 144hz monitor I want to get as high as fps as possible, this is the reason I am upgrading. on high settings it gets 50-60 fps in bf4 easily. Yes it's still a good card but if you are looking to buy one get the 7870 xt instead around the same price and a bit better even!