
It hurts to see the pt black dial PML after just getting the blue dial ss. I'd say that pt black dial is just about the nicest combo for a casual watch. Personally, I think that's the big difference. PML in black dial is casual while the senator of any kind is more a dress watch. Again, personally, I think the senator perpetual is one of the nicest executed perpetuals. Very nicely layed out dial, not busy at all. In terms of collecting, I think the pt black dial PML is a special edition that's no longer made while the senator is annually produced.
If I was given the choice, I'd take the pt black dial PML, even with my current PML.