We one shot it but I'm really impressed now by anyone who regularly heals with a controller. I'm sure it's just my muscle memory failing me, but I have no idea how anyone could manage higher level stuff like that. Is there some secret outside of constant practice?
Up and down on the D-pad scroll through your party list; this is like the #1 thing for healing on a controller, since if you try to cycle with left/right everything is terrible (also I have my left/right set to enemies only when unsheathed, so I can't even target people that way unless I sheathe my weapon.) Since the usually party list order is yourself up top, then tanks, then healers, then DPS, and it starts off by targeting you, it's up arrow to get to the DPS quicker, down arrow to get to the tanks/other healer.
The other thing that helps is getting familiar with the hard and soft targets on controller. The thing you initiate combat on or the first person you heal becomes your 'hard' target and you stay targeted on them until they die/you go out of range/you pick another hard target. You can then use left/right or up/down on the D-pad to cycle through enemies or party members, and as long as you don't hit X to lock them in as your hard target you have them 'soft' targeted. Basically you cast one spell or attack on them, and then your target will snap back to your hard target selection.
So if you're fighting a boss and mostly DPSing, but need to hit the tank with one heal, you can hit down on the D-pad to cycle through the party list until they're highlighted, cast a heal, and then your target snaps back to the boss. Likewise, if you're focused on healing the tank and want to just toss a DoT up on the boss, left/right on the D-pad until you have the boss selected, cast your DoT, target will snap back to the tank. Focused healing one tank and need to drop a pity heal on a party member? Scroll through party list with up/down, cast heal, target snaps back to tank.
I'm not a huge fan of alliance healing in 24-mans, because scrolling through those lists gets kind of annoying, but for dungeon and raid healing through Savage controller is surprisingly flexible and workable once you get familiar with it.