Right, I have only had it a week and got around to playing it for the first time last night.
I love FPS on the PC, and love the XBox as a console, but never got on with FPS, I had GoW and sold it as I got bored within half an hour, loved R6:Vegas.
With Halo3 I found the graphics were good, but not leading edge, the sounds are a bit flat, I would prefer the guns to sound more meaty, and the HUD to be clearer, playing on a 42" TV the top left and right corners can get mixed in with the sky and be hard to read when in the thick of it.
The controls are the good part, I love the dual weapon controls, it works really well.
The gameplay is the best part though, for a FPS on a console, I can actually hit stuff and kill them, the gameplay is fast paced and involving without dragging out cut scenes
Overall I love it, but I was struggling getting the online stuff working, it would let me create a room, but I couldn't seem to find any games
