I'd be tempted to call because of the bet sizing. From what you said he looks pretty smart... his SB steal prolly goes down significantly once you start to 3b light.
I'm feeling that his vbet sizing would be half pot or less just because Ax is a lot of your range here.
On the other hand when a reg repps a really thin range he usually has something in that range.

I guess it comes down to Aces up+ and flushdraws. I assume he's opening almost any 2 suited, so that would make it a call, and then there's the sizing. I think you can take off a couple of nut combos just because he would bet less with them... unless you have reads that he will vbet big I guess.
I call and make a note if he has a nut hand that he's vbetting too big when there's not much of a calling range. - 'repps blufs wif river vbet' or sumthin.