I voted Taxi, because im pretty much the only one that buys APC during the match. Though people rarely want a ride. So instead i provide support fire against infantry, aircraft, artillary and suppressive fire against snipers. The vehicle is pretty versatile, due to its good health pool and because the gun can reach certain angles due to its gun position. You can reach where no other infantry or tank cant. Very usefull when getting camped.
Meds don't seem to have much of a surival instinct. In one match i was at GDI wich was camping Nod's entrance. Nod managed to break through by destroying some mammy's and at that point i was in a APC, shooting snipers and sneaky Noddies. And for some reason all the meds where just standing there, looking for tanks to repair. But noone got the idea to get into the apc, get to base and like, save money and not giving away VP to Nod. People is med form are strange beings. As if they are stubbornly roleplaying bots.