That depends on what difficulty you play on. I go through the campaigns on Easy and Normal and never once have I had to adopt Camp or Die tactics.
I've always been able to run and gun. Halo 3 is the only game where the campaign felt a little short to me, and Bungie said from Day 1 that ODST wasn't going to be a full length game.
And I think the modding community was the worst part about Halo 2. I remember the days where every other game was filled with super jumpers, full auto BR's + auto headshots, and infinite shields. Plus that
infernal Noob Combo!
I don't mind losing, but losing to cheaters really sets off my nerd rage, and the Noob Combo took out pretty much all the variety that makes Halo great! Thank God for Bungie's banhammer. Honestly, I pretty much gave up on Halo's multiplayer after Halo 3. Battlefield: Bad Company 2, and soon to be Battlefield 3, is how I get my multiplayer fix. I infinitely prefer getting rewarded for playing smart vs. playing fast.