To clarify, 'effect-based' is a term HERO/CHAMPIONS has used for awhile to describe its system whereby you buy a power off a central list of powers, then fluff it how you like - so that a power might come from bionic implants, or alien physiology, or magic or psionics, but regardless its costed out the same way and has similar limitations.
Other parameters are often quite adjustable as well - one Energy Blast power could represent laser beams from the eyes, a magical lightning bolt, or what-have-you.

Other supers games have also worked similarly: most recently I think Mutants & Masterminds uses this approach?
Or Savage Worlds has a single powers list for super powers, 'weird science' devices, magic and psi.
 
Compare this to the 'traditional' approach - for instance in Palladium (Heroes Unlimited or Rifts), spells have their own list of effects, psionic powers their own list, bionics yet another list with specific advantages/disadvantages.  GURPS is fairly traditional, even though its points-driven like HERO.  
 
Anyone have preferences or insights as to which way is better, or the pros/cons of each?

I am of two minds on this. I usually like the concept better than the execution.

Most effect-based power systems either (a) don't really give you the tools to customize powers, resulting in things feeling very bland (exhibit A: Savage Worlds core) or (b) give you plenty of options for customization, but turn horribly complicated in the process (exhibit B: Hero/Champions).

Wild Talents actually struck a nice middle ground (the only reason it's no my go-to supers game is that I find combat too deadly), as did the alternative system in the Super Powers Companion for Savage Worlds (in which, on the other hand, combat not being deadly enough and presuming dozens of mooks to batter on each player is catually a feature if you're running four-color supers).

One game that was interesting was DC Heroes (Mayfair/MEGS), which was kind of a "middle ground" because you had "specific" powers (like say, Lightning or Sonic Beam or Flame Projection) and "generic" powers (Energy Blast, which was supposed to cover other types for energy projection).

Effect based powers are, by deliberate design choice, bland. They require effort (by writer, GM, or player) to make them into something more. By way of analogy, they are a list of ingredients (sugar, water, milk, flour, fruit), not a pie.

Good games, compelling games, require non-bland implementations. Melf's Acid Arrow, not the "Missle" power. Bigby's Crushing Hand, not "Entrap". And so forth.

As a writer/GM, even if you're working with an effect-based system, put some thought into making non-bland versions. That is, don't depend on the core book generics, make some specific versions. Give them flavor.

(And, as a writer, do some work on making different power systems distinctive. 3.0 clerics vs. sorcerers vs. wizards, as an example.)

As a player, recognize you have a responsibility to put the effort into making your character noteworthy and distinctive. (And as a GM, recognize this can be hard for new players, and do your best to help them.)

Effects based woks well when a player has a very clear idea of what kind of character the want to create before the game.

Otherwise, I find new players generally tend to prefer more guidance, so a set power list with described effects works better for them.

MSH (FASERIP) gives the best of both worlds, IMO, because it has a set list as well as the option of customizing an existing power or creating a new one in 2 very simple steps.

Thanks guys. I agree that effect-based systems are more bland - and getting a power to behave in accordance with its fluff seems to require some fiddling around with modifiers. Working with what people have and my own thoughts I have so far:

*effect-based is simpler to build - only need to construct a few powers instead of lots of detailed power subsystems. In the traditional system where powers and archetypes are specifically defined, more effort needs to be put in building everything individually.  (good I guess if you're a big company trying to sell lots of sourcebooks, bad if you're a lone designer trying to build a freerpg).

*effect-based systems allow a greater mismatch between rules and game reality: Energy Blast [fire bolt] works underwater or in vacuum unless the rules allow for broad interpretation of the fluff,  or allow you to add Limitation: requires free oxygen.
(and philosophically if my Fire Bolt is up against someone else's Vaccuum Generation power, who has to pay points to get their power to work? Should I have bought a limitation, or should he have bought a specific power to shut down the Bolt?)

*related to that, effect-based systems don't allow "power improvisation" - if you buy Flight as "Jet Boots", the GM may not let you burn the BBEGs face with your rocket exhaust since you should have bought Energy Blast separately for that effect, and it gives you an advantage based off the fluff you selected, over the guy whose Flight power represents a set of wings.

*world: a specifically designed system gives PCs in the world more idea what to expect from NPCs.

*effect-based can be more logical for some powers. Having 4 arms shouldn't work differently for cyborgs than for mutants, for instance.

*balance - does letting all PCs use the same power list in an effect-based system lock powers into those point values, when in other systems e.g. Palladium the value of abilities are much less definable???  (I wish I could explain this thought better).

I feel that no ruleset can possibly account for every possibility, and that generally it's best to keep the fiddly bits to a minimum and trust the GM to make the right call under the circumstances.

I'd rather put on a Fire "label" or descriptor on the Blast power and handle it with common sense (eg. doesn't work underwater or in a vacuum, sets cloth on fire, makes gas pumps explode etc.) Other descriptors such as Sonic, Electric, Radiation, Psionic, etc. have their own limitations and strengths, which may be broadly described in the book, but which the GM is supposed to handle with common sense and everyday knowledge of physics.

I think it's the GM's job to circumvent or modify or supplement the rules in the interest of common sense, suspension of disbelief and proper emulation.

Sounds sensible to me

I do hope someone comes up with an alternative viewpoint though.
I have seen 4E people elsewhere defending "re-fluffing" of powers by situation (the 'render prone' power acts vs. the horse by tripping it, or vs. the gelatinous cube by squashing it so it needs a round to reform, whatever). But I much prefer the commonsense approach.

I think the optimal approach is to have a bunch of detailed, idiosyncratic powers in the main book -- and then have rules for creating custom builds in the appendix.

I like having detailed and differentiated power descriptions (fire should burn and spread, electricity should fry everyone in the pool, etc.), but even a gigantic powers list won't cover everything I'd want to do in a super hero universe, so there should be rules for extending the basic listing.

Cheers,
-E.