A well developed quest system also has it's perks. I really enjoyed picking up 20 quests, doing them for 1-2h hours and cashing them all in at once. But it's always annoying if there is a lot of running around without anything to do in between included.

I would not call the heart system perfekt or great, because there are a lot of hearts, that are completing very slow or require tedious tasks. It's also annoying that progress is not shared in a group. But the system is unique and most tasks are fun.