If you noticed something funky happening with the leveling system, it actually was for a good cause. We've done an investigation in the past week to find some interesting details about our profile leveling system. Check out our full report about what happened and how we fixed it.
Except at the earliest levels, they're just a bit of fun. With the revamped system I imagine we'll see more users power-leveling.
There is nothing wrong with the system except for the amount of experience required to move up in levels such as 63/64.