Most are terrible at being a medic anyway, this makes no difference to that. The dedicated medic will be just fine. I racked up alot of points just being a medic in the beta.Its hard enough to convince people to revive. Anything that makes it harder is going to discourage it. Its bad.
I think I would prefer the gadget be med packs you throw to people. Yeah it looks stupid when they lock on to people but at least it works.
Those small health packs would be great, but they aren't in the game. Atleast if the med crate is the gadget you could also use the ammo crate to fill out your support.