The new production 1As are only available with a 26.0mm clamp. I think you can find Nitto Dynamics with 25.4mm or 26.0mm. To me it would come down to the other components on the bike. A matching Nitto seatpost would be a nice touch.

As for vertical adjustability, I think the new 1As and the Nitto Dynamic are about equal; perhaps the Nitto is a cm or so taller. The Nitto has a 72d angle while the Cinelli's is 73d, so there's that.

If anyone comes across a Nitto Dynamic II with 80-90mm reach please let me know.