Guildleves, on the other hand, I'm not too sold on. Anything that gets me out into the open world is good, but I disliked everything about the system apart from its being a way to manually spawn mobs or nodes that, upon killing/gathering all, gave somewhat meaningful experience.
I'd much rather the world itself be designed in such a way as to make little mob ecosystems or playgrounds of sorts, ideally as could lead to increasing access to further, reasonably rewarding challenges with exp gathered there, such as by spawning harder mobs, triggering events, etc.