I've only invested about 60 minutes so far into Battlefield 3 Close Quarters and atm, I can't say I'm terribly impressed.
Currently I've only played Ziba Tower, Donya Fortress and Operation 925 and as cool as they look, the gameplay seems to be virtually identical map to map.
Right now the coolest part is that so many online are still unfamiliar with the maps that Squads, even Teams, tend to stick together. Unfortunately with so many lurk spots abound in each map, that will likely change into a campfest.
The other issue which has been documented on YouTube is that you will likely see a huge rise in C4 and Claymore usage. The Flag Zones are so tight that you can take out half a Team with 3 or 4 packs of C4.
I saw one video commentary where 4 or 5 medics simply camped a point with shotguns and continually rez'd each other when killed. The flag itself became virtually uncappable from that point on.
It will be interesting to see how gameplay changes as map familiarity grows but so far IMHO this isn't the best map design I've seen and the constant run 'n gun method of play gets real old real fast.
I think those that like Metro are going to love this expansion but those of us who like a better mix of wide open and adjustable tempo gameplay are going to find themselves way out of their element.
I guess time will tell.