Personally, I'm inclined to believe the framerate will be locked at 30 at all times. I think 343 knows the problems forge world, and even some campaign environments in Reach caused. Only problem I'm seeing is a huge increase in graphics. At least from the pictures and such that we got. That might cause performance problems.
Reach netcode is so good its only comparable to Gears 3 for me. And I don't play on Gears Dedi's. If they have the same netcode, then I'd be content. Dedi's would be nice, but its not huge priority imo. Halo netcode is good enough to warrant spending resources on other things.
60 FPS would be nice, but if Halo 4 can manage a steady locked 30, that'd be perfect. I've said it before and I'll say it again. It's not the number of frames per second that matters. It's the consistency.
Recoil seems negligible. From your statements and from memories of the Reach Beta DMR.
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My big issue with Halo 4 will be the Ordanance System, the armor mods, Armor abilities, loadouts, and sprint getting annoying. Those are things I still need 343 to prove they're doing right, because I don't like what's been said about them already.