In T1, my experience is that the priority checkpoint on the left (between 1K and GS checkin) is most efficient - much more so than the one down by LH.

They are often operating the full body xray wizmos down there, but they typically (IME) are only able to staff one of them, so, after getting your ID checked you should just bear right and merge in to the front of the lanes being fed by the normal traveler queue.