here's a blind guess. i'm gonna guess none of you ever saw a medic hand out a health/med pack.
and i'm also gonna guess you did see medics hand out health buffs.

since a medic should be healing, yet it seems there is no health pack, that would mean the buff heals, no?

that was all based on the seemingly absence of med packs though. this post is scrap if we come across a medic healing someone while his health doesn't get buffed.

Iirc a buff does heal you. At least a friend of mine who played medic throughout in the demo did tell me he constantly buffed/healed himself (also boosting himself up the leaderboard that way).

i think that you have health regen and a health buff just makes you tougher but if your health is low a medic can heal you instantly

The question is whether the health buff just puts people to 120% health automatically, and there is no lesser heal, or if there is a heal that gives 100% health, and then a boost that does 20% on top of that. Rev has actually played the game, so I'm bound to trust his reports more than speculation.

In that case, I would assume that the health buffs are just upgrades of the base heal skill, which would make sense. The other classes get upgrades for their basic skills - better turrets, faster hacking and planting, only place to improve healing would be to make it a buff.