Philosophy of Partial Powers

• There seem to be fairly clear limits to powers. That is, Corwin has a series of tricks that he knows how to do with Pattern, and that's it. Fiona may have more tricks, but she, too, is limited to a defined number. Of course, these tricks may be fairly versatile — Gérard was pretty amazed when Corwin destroyed part of the Black Road with his Pattern Defense. But none the less, Corwin wasn't doing anything new with those powers, he was just pushing harder with what he had.
• People don't necessarily follow the same paths to the higher powers. Both Brand and Caine pretty clearly had powerful Trump abilities, but there's no real indication that Brand could do the sort of spying that Caine could do, and Caine obviously didn't have Brand's "Living Trump" powers. For these two reasons, I don't like the concept of "powers as stats" (that is, just bidding any number of points in, say, Pattern).
• There are very few dabblers in the Amber Universe. If you do something, you tend to commit to it. Even Merlin, who dabbles a lot more than most, has brought himself to at least general comptency in all his powers. For this reason, I try to make my partial powers systems have relatively high-priced initial powers, which represent the steps of learning those powers (or being initiated into them). If you're going to learn a power, be prepared to commit some fairly serious points to it.
• There is no indication that anyone who has walked the Pattern can't Shadowwalk, or, indeed, perform most of the tricks that Corwin could. For this reason, despite this being a "partial powers" system, there's a big chunck of a power to buy for Logrus and Pattern (less in the second version of the powers).