Harrison hooter is the most realistic owl hoot I've heard / used in the woods (I have a walnut - but I doubt there is much difference to synthetic). If a bird is going to shock gobble at a hoot - then he can't resist this one.
Had to laugh last year at camp - went out to listen / roost prior to the opener. Got into some hootin' chatter with the locals. We had 5 owls follow us back to camp - landing in the trees above us and carrying on. Cool (and a little creepy!)