Nice pen - great nib, though wider than usual (maybe even moreso than the typical Lamy widths). I've got an F that I'd call a M, and an OM that I'd call an OB. But really, they are classic pens and an important pen in the Lamy lineup.
If you compare to the L2K, the tactile feel of the Profil series isn't even close to the quality of the L2K. The plastic (Makrolon) isn't finished much, just sort of a normal plastic casting feel. The piston assembly is virtually the same, though I and others have experienced some play in the piston knob (recent thread here about it). The cap of my 81 is exceptional quality, up to the standards of the L2K, but the plastic cap on the 80 is lesser, in my opinion.
But really, the high point of the Profil series is the big ol' plated 14k nib, which exhibits a little spring to it and is a nice wet writer. Just don't get an EF and expect it to compete with fine line writing of other pens (using my sample size of 2 nibs).