Armor Lock isn't overpowered. You just suck at Reach :)
Reach isn't bad, you're just a BK :)
For my gamertag, look up "Ghoulishtie"
It's all up to bungie.
Put it this way. In halo 1, they did implant the health pack system. However, that was back on Xbox, and like all other games, they also used health pack systems.
Once Xbox started to get to its higher limits though, Halo 2 was going with the flow, and updated the health system.
Now on 360, you rarely see health packs on these kind of games. So I highly doubt we would see Halo 1's health syle come back.
Besides, I perfer the new system. It would ruin alot of Halo: Reach if they returned to Halo 1's system.