Neutral.
It's part of the medics job to know where and when to be to provide medical attention. Medics aren't errand boys and shouldn't be running across the map to a group of soldiers who's medic died or they neglected to bring a medic with them so they can be healed.
That being said, it's best to leave class boosts alone and focus on battalion buffs. If medics get a speed boost, then other classes will want boosts. However, a better med pack that heals faster would probably be a better suggestion, that way you aren't stuck as long healing the person.