Attila is really good. It was probably the most polished Total War release since...ever, now that I think about it. There are not as many playable factions, and the map is even larger than Rome 2's, but the new features, enhanced graphics, and decent AI make it a solid purchase. Being able to completely destroy a city off the map or migrate your entire faction in hordes (essentially mobile cities) is really fun.
CA/SEGA are still shady with their DLC, though. Release a game with only a few factions/unique units, then charge $7.50 for faction/unit packs after release. But once the Steam workshop is integrated with Attila, mods should make up for this.