Can anyone see any balance issues in moving the aspect down a few levels (and by a few, I mean down to 2 or 4, so a lot)? It's a really neat, flavorful ability, and I feel like the only reason it was put that far into the progression was to avoid a dead space in the table (in which case, you can stick an Improved Aspect that lets you transfer more evolution points to yourself, but at the normal 1 for 1 cost, with Greater Aspect remaining as is).
I'm really not looking for a power boost out of this (and since it takes from the Eidolon, I don't think it would be anyway). I just want to be able to use the ability earlier. (I may actually playtest it getting that ability at 2nd level and getting an Improved Aspect ability if possible this weekend.)
Aspect allows the summoner to attain permanent, resource-free flight, which probably isn't appropriate for such low levels.
Come to think of it, I don't think I could see myself spending my aspect points on anything but flight. The first time I'd have to think about what to do with aspect is when greater aspect kicks in, which is so late in the class' career that it's not worth thinking much about. I'd definitely like to see some sort of intermediate aspect to bridge the gap.
The summoner effectively gets access to that at 6th level anyway (and that's assuming a Medium-size summoner). I'm assuming all level requirements will remain the same. That said, you could always double the level requirements when using the aspect ability, so a summoner couldn't get flight until 10th level.