I use mouseover macros for every single-target healing action. I prefer them because I can watch a target ring, enmity bars and buffs/debuffs of target enemy when I heal.
Macros can be pseudo-queued by repeating same commands like this.
/merror off
/ac "Cure" <mo>
/ac "Cure" <mo>
/ac "Cure" <mo>
/ac "Cure" <mo>
/ac "Cure" <mo>
/ac "Cure" <mo>
/ac "Cure" <mo>
/ac "Cure" <mo>
/ac "Cure" <mo>
/ac "Cure" <mo>
/ac "Cure" <mo>
/ac "Cure" <mo>
/ac "Cure" <mo>
/micon "Cure"
Its pseudo-queueing window is about 0.46 secs in 30 fps.
I found macros useful when I play PvP. When my spells are interrupted, raw spells are simply canceled but macros can be recasted immediately. When I want to cast non-instant healing spells after I move, I can execute macros before I stop. I can also execute macros when the target is out of range or out of sight.