When RTR came out, it was a nice change from the original maps.
I played it a fair amount for a month or so.
Now there aren't really that many servers running it.
When I rebuilt my system a couple months ago, I didn't even bother installing RTR because I had no desire to play it.
If you can find it for like $10 it's probably worth picking up just for a change of pace for awhile. There are some decent maps in it.
Yes, DC has new maps.
I think they are now up to 7 or 8 custom DC maps.
But yeah, I'd say you will stay entertained for a long time with just the original BF and DC.
The other thing is that the Forgotten Hope mod is coming out in a week or two.
It retains the same ww2 theme, but adds a ton of new maps and vehicles.
Obviously we don't know how good it will be, but it looks more like a really good expansion than a mod.