For an upcoming setting, I'm looking at combining the core Savage Worlds super powers arcane background with the No Power Points setting rule. This has some pros and cons. One major advantage is the ability to maintain a power indefinitely - so a hero with the Speed power can keep running at his accelerated pace as long as he likes (making a Flash-type speedster more possible without going to the Super Powers Companion rules). In general, the idea of a superhero "losing energy" in the power points model doesn't sit well - imagine if Wolverine could only heal for a little while or Spiderman eventually started falling off walls. There are some exceptions (web fluid, anyone), but mostly, the no power points approach feels more like traditional superheroing.
The one catch I've found is that, for some of the higher level powers, the penalty (1/2 the power point cost) is pretty severe. A superhero taking invisibility, for example, is automatically running at a -2 penalty every time he tries to vanish. Want to shape-shift into a bear? -3. These are big penalties in Savage Worlds terms - a character with a -2 penalty on a d4 skill is effectively unskilled at that power.
What I'm experimenting with to offset this catch is using a modification of the Born a Hero setting rule. If characters can add any power at any level, rather than limiting their abilities to the nominal Power rank, then they have time to build up those skills to the point of usefulness. For Invisibility to work 50% of the time, as an example, you need a d10 in the skill. (A d8 gives you a 48% chance, a d10 gives you a 58% chance). Given that advances in Superpower skills are cheap, this might be good enough to give a superpowers feel, but I'm not sure yet. The other setting rule I'm contemplating is that powers always work outside of combat. This idea would reflect that combat is stressful, and give the superhero the chance to shape shift or go invisible reliably before the fight starts. I'm certainly open to other ideas - has anyone experimented with the core book superpowers in this way?