I think that applies well generally to ARTCC/tracons.
When I visited my future tower (a level 6) I was told that once you certify on ground you get a payraise over 10k. However they only have ground and local, so that would constitute 50% of positions.
At a place with clearance/ground/local, then when you certify on clearance, you will have checked out on 33% of positions... (which I imagine they'd have to give you a raise to D2)
That makes sense... and you'd hope they give you a raise to D2 if you check out on 33%, but it's the FAA so who knows :crazy: