My group played Supers for years. Of all the super hero games that we'd tried over the years ( Villians and Vigilantes, Marvel, DC, Champions, Heroes Unlimited, HERO, TMNT, Underground, Aeon/Trinity/Abberant and Brave New World ) we loved GURPS best. Maybe because it had the greatest depth of customization, on par with old school Champions, but the system was easier and used a ( lot ) less dice. Maybe because we were already old hand at GURPS and playing Supers wasn't really that huge a learning curve.
We played 500+ point characters and did full bore 4 color champaigns, often dark, sometimes funny, always deadly. The deadly was by choice, we played a kind of Dark Avengers story-line to put it in todays terms. One thing I can say, fatigue is a killer. We learned very quickly that powers that caused fatigue drain or that used your own fatigue or not having extra fatigue or a good defense for it would get you killed faster than some guy doing 100 points of dmg if he hit.
Plus a GM must always balance his foes so that they are challenging and appropriate for his heroes. An old Adventurers Magazine champaign had a senario called Gilt Complex that pitted your super team against a seemingly very powerful villian group. One villian could hurl tanks or buildings at you, problem was when your tank type went up against him throwing 100 point punches and his fist went clear through him you realized the villian was all streangth and no defense. oops! Now you get to roleplay a hero on the lam or in jail for murder! Other villians in the group had similar defects that went against comic book norms, such as a psychic with no mind shield, or a speedster with no dodge. Really gave the players a jolt, made them concider thier actions.
Someday, somebody else, besides me, will call me by my stage name , they will, call me Dr. Verm...