I disagree with adding limits to leveling speed. All content can be experienced at max level and can still be challenging. I believe this was one of the firsts City of Heroes had. Leveling gets tedious especially with the amount of characters, combinations and customizations you can have in this game, all while trying to find something you will enjoy the most at max level.
Here's an example of my goal when I create a character.
- Get to level 50 as quickly as possible.
Now that I have that done... I can do the following without being limited or restricted based on my level or worrying about being slowed down due to one thing or another (debt, influence, enhancements).
- Experience Game Story & Content.
- Refine my build.
- Grind out influence.
- Help out and power level friends.
- Hunt for badges and accolades.
- Create quality architect content I can test at both low, mid and high levels.
- Create and experiment with a new character, knowing I have a max I can switch to if I need.
- Queue for anything and everything.