I would say yes, it's worth it. It has already been mentioned that it's overall cheaper if you know you're going to buy all the map packs anyway. I think it's around $15 per map pack. Some people might already have B2K, but if not 5x15 would be $75. And even if you take B2K out of the equation, it's overall still a better deal ($10 less). But if you don't plan on buying all the maps, I guess stay away.

The other positive (for me at least) is that you get the maps earlier. There's also weapon and soldier camos and special assignments for Premium players (the first one had dog tags as rewards). In a way it does add a little more stuff to do for players. And if you really want to milk it out you can say that you get game guides and videos (although this can be found for free online anyway if you know where to search probably -- which is somewhat of a bummer).

I don't think that the weapons are for Premium players only, but they are rather tied to the DLC actually. Anyway, if you think you're going to want to keep playing this game it's definitely worth buying.