There is more to it than that of course. A strong healing cleric is all about keeping the rest of the party running. You need to make sure you have LOS to combatants, arn't pulliung agro, keep buffs up on allies, spot cc mosnters, thow out DV's, etc... A good healbot makes it so the party doesn't even need to think about survival and can just plow forward at top speed.
Healbots are most fun when the adventure is a good solid challenge for the group. If its a cakewalk its really boring because they just don't need you. But if the party is teetering on the brink of death in the tough fights, playing a main healer is pretty exciting and demanding.