If you really enjoy the game, then go for it. I bought Premium because I knew I was going to buy all the DLCs anyways, and it saves a bit of money. Honestly, all the other Premium perks (dogtags, assignments, etc.) are just meh.
Otherwise, just buying select DLCs is fine. The new Aftermath maps are a lot of fun. I also like Close Quarters because it's fast paced and adds some nice weapons. Armored Kill is alright, but you can skip this one.