Ranked in these QuestionsQuestion Ranking
Pros
Pro Rifts are fun
Rifts are small event-like things that spawn randomly throughout each non-city zone. You run into them, complete the objectives, and are rewarded. The exp is really good for lower-levels. There are also zone-wide events that are also very rewarding and involve multiple rifts.
Pro Good reasons to explore the world
There are puzzles, platforming gauntlets, collectibles, rare mobs, and more to find in each zone. The zones are more than just "containers" for quests.