AA is a hard commodity to judge because his AHL seasons have been interrupted by unfortunate and random injuries and his sample size at NHL level is small.
But basically he bottoms out as a defensively ok 3rd line centre/wing with blazing speed and a high probability of 15-20 goals a year.
His peak projection might be as a borderline 1st/2nd line winger or 2nd line center who could put up 50-60 with the right linemates if his passing improves, with the potential for the odd monster season.
His absolute peak would be super budget Fedorov for a season or two, but that would be dreamland territory.
Is he Darren Helm with great hands (which actually would be a good hockey player before anyone cries foul) or can he elevate his all-round game to something more complete.
One thing is clear, his skillset means that he can be just as effective at NHL level as AHL, because in a tight, tactical game, someone with great speed and hands can break beyond the systems stifling the NHL with greater regularity than a more skilled but less dynamic AHL points monster.
I think what makes most wings fans very reluctant to see him be traded is a combination of the raw excitement he brings to the rink, that capacity to be dangerous at any point in any game, and the way his all round game is growing quicker than one would expect given his starting point. Good chemistry with Mantha doesn't hurt either.
Like others have said, he may be worth more to Detroit than buying teams because blazing speed and finishing ability are not exactly in excess supply on the wings roster. So while to most teams he's not worth much more than a late 1st rounder, to the wings he's probably worth a top 10 pick in a good draft year.