I constantly found myself going back and forth graphically everytime I got to landmarks that I remembered fondly in the original game. I would go into old graphics, approach something, swap to new, and just be amazed by the difference. The only thing that bugged me about was the things they resized. Extras added to things like the tank were transparent and could go through things like they didn't exist and things that were scaled back like Cliff Edges still physically existed in their original state, so you would get stuck on invisible walls when driving vehicles. Not much of an issue. Just a minor nit-pick of mine.
Honestly I'm not against them doing the thing with the H4 and map packs this time anyway. Halo 4's multiplayer isn't bad IMO. It just needs more content. I require more maps and more playlists and I'd be happy with it (Super psyched that Grif Ball is almost here!)