Eh, I don't see H2A as being particularly worthwhile.
H2's campaign was a clusterfuck and boring as hell. It's the only (Bungie-made) Halo campaign I've only completed once. A shiny gold-plated turd is still a turd.
I loved Halo 2's multiplayer, but most of that was due to the high quality of the maps. There were a huge amount of bad gameplay decisions. Now if you had H2's maps, netcode from Reach, features from later on in the franchise (forge, saved films, file share) and fixed the many sandbox problems with H2 (ditch dual wielding, ridiculous tracking on plasma pistol, power weapon spawns, etc.), I'd be all over that, and would probably buy an Xbone just to play it.
