I think its kind of funny discussing Power level in a role-playing game. Sure, any wizard could crank out 25+ on a Spell-casting Roll on a regular basis, but should you do it every time? No. Why? Well because then the GM will have to start creating challenges so bad-add and in such numbers that all the other non-caster characters are getting turned to pudding when the bad guys sneeze.
Sure, the GM COULD use a bunch of lesser-powered bad guys but while the caster is taking out the baddest of them again his non-caster allies are getting their butts handed to them again.
A smart caster would conserve his energies and make sure his allies will make it through the fight in as close to one piece as possible. Or find alternative uses for magic other than Blasting everything in sight....which after the first 10 or so times of doing that it gets boring, not just for the GM or the player in question but for the rest of the players as well.
"Oh crap a dragon!"
"No worries Fred will get it, we'll just stand over here and watch."
*yawn*
"Is it over yet?"
Point being that its a GAME and its meant to be fun for everyone playing, including the GM who has spent hours crafting a fun scenario and challenging opponents only to see them melt away in an eye-blink because someone who could overdo things but didn't really need to decided to go ahead anyway.
ANY system breaks when someone sees a way to exploit a system and goes for broke. The systems don't break if they aren't abused and having played or run probably a few hundred game sin my nearly 30 years of gaming I think I can say that with some authority. Though there ARE systems that are built to be broken and playing with that kind of power is fun because everyone is doing it. In a game like the Dresden Files the emphasis is on Role-Play, heroic role-play to be sure, but Role-play.
To Quote Ben Parker; "With great power comes great responsibility"
But hey, for folks that want to play in high-powered, building leveling games and have a group that wants to do that more power to you and have fun! That's what the game is all about!
As a Note (this was talked about in the Sponsored magic thread as well); YS288 Bottom paragraph of the right-hand Column essentially states that you can only incur One Sponsor debt per Roll and that Debt can only be used to Tag an Aspect, not give an automatic +2 on the roll. So no more grabbing 4 points of Sponsor Debt for +8 to the roll! Of course a truly forgiving (and possibly very drunk) GM may allow it anyway, tailor your game as you like. (Don't be shocked, I DO read rules).
DFRPG has a steep learning curve so getting everyone up to speed is not going to be fast or easy especially for folks who have been used to entirely different sets of mechanics that aren't nearly so flexible.