From what little comparison I have done I would say that their ss and tube pre-amps have similar sonic signitures.
Yes they mostly are similar. I am more familiar with the older models. The PF1 & PF2 solid state are tube-like, being more to the clean/quiet side, which you would suspect I guess.
The top of the line solid state like the old PFR are actually closer to dead neutral than being tube-like.
I owned a couple of the higher end Motif line that came before the PF line. The Motif MC-8 later became the PF1 & 2; The MC-10 later became the PFR. The designs were almost the same, the Motif line just higher parts quality in places.