Half right.
There are two Look heels in question, the "turntable" and the "pivot". Trouble is that Look uses the "P" designation for both types.
This is the Turntable heel:
This is the Pivot heel:
The P18 and FKS185 and the same, and have the turntable heel.
The P
15 and FKS155 are the same (though I doubt you'll ever happen across a pair of P15s, they're rare in the states)
The P14, P12, and P10 have a different heel, the pivot heel.
The toes are also different, P18/P15 toes are all metal and have no vertical release. All others have at least some plastic and do have vertical release.