Part of what puts Luke above the rest for me, is probably bias in watching what Quinton has done, with just getting better and making those exponential leaps year over year. See a lot of the same starting to happen with Luke.
With Edvinsson, i'd agree...he could very realistically become the best of the bunch defensively, but i'm not sure how much offense will come with that.
Power to me is a tough read in some ways. The offense is there, and there's really no particularly reason to think that the defensive side won't eventually come. But he's definitely a lot more passive defensively and has some pretty brutal moments. If he can cut down on those "ooopsie" moments though, i think he's got every ability to be a solid defensive player. He's got all the tools and he seems to generally be a pretty smart player with good vision on the ice.