I've played it, and it's not as bad as this thread makes it seem. Actually, it can be fun if:
1) Everyone can calculate things / add up dice quickly.
2) The DM and players have an agreement not to break the system, and of what constitutes broken.
3) The DM sets up a few basic power caps (most importantly, a SPD cap).
Even then, battles tend toward the long side, and character creation isn't fast (think high-level D&D character, including picking out items and prepared spells). But it does have certain advantages.
Advantages:
* You can make exactly the character you want. Down to each individual power having exactly the effects and usage conditions you imagine.
* You don't have to make "rounded" characters. This is can be a problem, especially with new players/DMs, but it also gives you freedom to make a radically different character without being forced to have X combat ability for every Y skill, or X defense for every Y offense.
* The combat system actually results in the kind of stuff you'd expect superheroes to do - throwing people through walls, sending foes flying with a mighty punch, tossing a truck at someone - all works without fudging.
Disadvantages:
* When making a character, you need to know the desired goal first, and then pick out stuff to fit it. If you try to just dive in the way you can with D&D, it'll be confusing and hard to get good results.
* Character creation is always fairly lengthy, and unless you have a player/DM with some experience, you can end up with a character that just doesn't work.
* The system has loopholes you could drive a truck through, and if you have even the slightest inclination to break it, you can easily get a world-shatteringly powerful character. The DM pretty much has to set their own standard of balance and enforce it, because the rules don't.
* Combat is slow at best, and if any of the players are slow with math, it goes about as fast as a glacier.
Basically, a great system for creating a specific character idea you have, and a terrible one for running a quick game.