I've been playing for almost a year now, as WHM up until maybe 2 months ago when I switched to AST. To be honest I don't notice any difference or feel that the range is too small. Before HW I'd always keep Medica II up non stop on everyone. However now that I'm at 60 I feel that I understand strategy more, and am more careful if there's adds about to spawn and so on, as usually Regen on the tanks is enough as is. Since I got into that mind set, I only would use Medica II when really necessary, otherwise sticking to just Medica for lesser MP and bit shorter cast time. As AST I do the same, only popping it when completely necessary even if it means doing it twice once at each side.

This is what makes AST so much fun. At first it seems like MP is an issue, but you'll see once you start to play it more. You can always Spread an Ewer card to hold on to it in case you need it later, especially if you have a buff up from Royal Road like the enhanced potency or extended time one. There's popping Spear on yourself before Luminiferous Aether followed by a Celestial Opposition to make it come off cool down quicker but also keep the buff up longer as well. Things like that, lots of fun combos you'll be able to do to maximize the tools you have to get more MP. Remember Light Speed as well, it's a 25% MP reduction I believe it is, so when things get really bad I pop that and hit a Helios once or twice.