i like it

i was watching some videos on halo: waypoint lastnight and it said armor was cosmetic only

The thing that irritates me about the armor is that its ONLY cosmetic. All these points you accumulate, commendations you get, etc. and your avatar just looks a little different then everybody else in the lobby. What is the point? Armor effects would give me so much more motivation! As previously said, it wouldn't be hard to code because we aren't talking about game changing abilities like the Armor abilities. I'm talking about small improvements to further specialize your play style. Also, since the trueskill system matches you up evenly, new players wouldnt be matched up with advanced players with better armor bonuses.
I also love the previous poster's idea of different HUDs for different helmets. Awesome idea.

Different HUD for Different Helms is all I want

Otherwise: No, Armor SHOULD be Cosmetic only.

I think armor should have minor effects too. VERY minor. Noticeable maybe, in a ridiculously close 1 on 1 match where you survive by the skin of your teeth. That way it's easy to balance, and doesn't completely screw over someone with fewer upgrades. It should affect things like durations of abilities/health/armor, but not respawn time. I think that's too cheap. Mixing and matching would allow a little improvement for different layouts, or choosing all armor for one layout makes that one stronger but reduces versatility. I know how useful it is to change layouts mid-battle depending on circumstance...

If armor is not to have any effect on things, at least make them more than simply cosmetic. I like the HUD idea.

I agree I think that armour permutations should do something to not just Armour abilitys such as scout\ faster sprint. But also normal things like EOD\ less explosive damage and so on. But they should add to some and take from others e.g. Scout\ faster sprint: less explosive damage resistance and the oposite with the EOD armour\ less explosive damage: slower sprint or Para armour\ longer jet pack duration: more visable when invisable. But you get the poin so yeah there's my opinion and I hope it gets into the game.