Sup dudes, I've been having Halo 2 LAN parties every night for a month and thought I'd bump this thread.
I've still barely played single player. They may as well have called it Halo: Arena and left it out, lollers. I'm loving the XBox live interface (although I've been mostly playing LAN) - the voice messaging and built-in clan stuff is the shizzle.
On weapon balance: the sword is a little bit overpowered, I think, but not a lot. The disadvantages are that it glows like Christmas (even with active camo), everyone wants to take it, and basically can NOT beat a good mid-range pair of weapons (as long as play proper-keep-away). Also, the sword always spawns in a central or high-traffic area, making it pretty dangerous to go for (although it's still worth the reward). So, yeah, all it takes to beat "the sword guy" is to use your head. Also, if you don't suck at the game, you can beat a sword guy dashing at you mid swing with a shotgun.
The Rocket Launcher is deadly as shizzle, though. The only balance to it is the small amount of ammo included. Protip lol: the Banshee can still easily roll out of the way of homed rockets like what.
The charge-up pistol and ANYTHING can be pretty deadly. A needler is suck, but 2X needlers can be pretty hot, especially the way they'll chew through an overshield.
On the side of glitches and other horrible things, there are more than a couple horrible, implausible areas that players can get to via jumping on each others' heads, vehicle voodoo, etc. Sometimes, it's just an awesome reward for being clever (like team jumping a 1-flag-ctf guy up to the sniper window in Zanzibar, or getting on the roof of the base there), but when a flag carrier can ride on his friend's banshee up to god knows where and get to an invisible-edge-of-the-world-stupid-glitch-place (or just return the flag in five seconds), something is definitely up. Like, check out Headlong. Look out towards the ocean from the overpass where the overshield and rockets spawn. Then check out the buildings on the left, going out to the ocean. Look up towards the very furthest corner. Yeah, we've been there, being a sniping son of a bitch. Also, we've been "on top" of Foundation where it's impossible to even fire or throw grenades up to. (LOL) Fortunately, the way of getting up there is pretty much impractical for any serious match. With the Banshee and a million extra fdisking places to hide, Bungie definitely didn't do any sniper rifle nerfing.
Oh yeah, XBox live name is SuperTy