As many times as you can use a sword before it becomes boring. Which is why Derplander has changed his job and weapon with every expansion (twice for SB). As I said, showcasing a healer needs the WoL to take on a more reactive than proactive stance, focusing on fixing things rather than destroying an enemy. Healer LB3s ARE visually stunning as is; and both of the examples I listed are more than using a (very impressive) shield for 5 seconds and healing someone for half of one.
I mean, if you have a bunch of soldiers dying and the WoL is walking through shooting spells at everyone, they start standing up until he's walking in front of a veritable army, THAT'S impressive.