Hey Robert,
That's a great question. We noticed similar issues. The goal with Aspect was to have a slow refinement of power level and to prevent power creep, but it is not as satisfying as we'd like. We did include alternate advancement rules, but those are not the primary method supported in the system.
Aspect is not dead. I have a new rulebook I have been working on since 2015 that will address the advancement rules as well as a few other issues that have cropped up. Here are a few things I am trying to address:
More flexibility in fewer pages
Even faster combat without sacrificing strategic choices
Faster character creation
Same goals as Aspect (no 15 minute day, every character is viable, functional flavor, everything at will, etc)
More flexibility in fewer pages: I have a formula I use to balance all the powers in Aspect. All 1000+ of them. I had originally planned to release the formula for players to make their own stuff. In preparation for doing so I accidentally stumbled upon a grand unified theory for Aspect powers. I am working out the kinks, but it involves an overhaul of the core die mechanic. I am REALLY jazzed about this.
Faster combat without sacrificing strategic choices: Oddly, the above ties right into this. What we currently think of as powers now can be built on the fly during combat with zero math needed from the player (other than small single digit addition or subtraction). The actual resolution of an action is done with a single roll. Position, movement, flanking, stuns, buffs, debuffs, healing, etc, all still figure into the game, but their math is also now much simpler. The dice do the math for us using probability.
Faster character creation: Creation now takes about 15 minutes for choosing options of stats / race / powers / and calculating defenses. The rest of the time is as much time as you like figuring out flavor for your gear, your character's motivations, etc. It all easily fits on a single sheet of paper now. I have watched multiple 4 year old kids make characters. The character ideas have gotten much more creative because we have further unleashed the imagination of our players.
Our feedback so far has been phenomenally positive. I think when you get a chance to look at it, you're going to love it as much as we do.