If for whatever reason you wanted to run a Mighty Protectors campaign using the levels and experience rules from V&V 2.1, then you could use the chart shown below.
Using the old experience rules would likely make for significantly slower character progression, depending on how much XP the GM awarded per gaming session, but it would also allow for more granularity when it comes to rewarding — or penalizing — characters.
You could also add a Karma* system, a la the FASERIP system, on top of the xp system, which some players would love (points at Dennis), and some would hate (points at Jeff).
* Mutants & Masterminds has something similar with their Hero Points; it’s just small numbers
Superhero RPG Musings 