Healing skills
It really depends on the situation. If I’m with pugs in fotm or a dungeon, I bring HaO because it heals for drastically more than HS. I guess TU would be even more beneficial, but I prefer a burst heal. If running with guildies, I bring HS to help support the group. In W3 it really depends on where I am. Defending a tower? HaO. Ganking dolyaks? HS. Roaming? Depends on party composition, but usually healing spring for the condition removal.
If you are in the front lines, HS is better for the condition removal and long 15s water field for allies to combo. If you are in the back with a 1500 range longbow, HaO is usually better. Just know that the cooldown on HS is much longer than HaO, so if you run into trouble, be ready to back off because you won’t be able to heal for a bit.
With a build partially focussed on regeneration and group support, Healing Spring is the vastly superior choice for me.