I haven't really thought about it before but in terms of desirability/quality/etc. I'd say this...
BJFe -- the flagship line that offers the best of everything, quality, desirability, tone etc. Often times the rarer ones border on pieces in a collection for some rather than tools. I am personally trying to make sure I use and abuse each and every one of my BJFe's because they don't do much for me sitting in their boxes
Also, this is the brand which seems to unveil the newest/greatest/uniquest designs while the others seem to produce the more mainstream models (at the moment) so if you want unique (MH, MR, MG, MGMV, etc.) this seems to be the only way to get it (currently)
BearFoot -- the new kid on the block whose goal is to bring the BJFe line to the masses in the truest way possible. In contrast to the MP line I expect these to be 98% + true tonally to the originals with the only losses being in the "handmade" aspects of the pedals (finish and lettering). I expect these to actually boost the desirability of the BJFe pedals too as they will kind of be the gateway drug to the brand. I do consider these to be a part of the BJFe line unlike the next two...
Mad Professor -- These are the production model pedals that are designed by Bjorn, but ultimately built and sold by an entirely different brand. I think they are a more simplified version of BJ's designs in that they are desinged in such a way that component choice and matching isn't that critical to the overall tone. This leads me to feel that they will not have quite the same feel as the BJFe and (hopefully) BearFoot pedals due to the less rigorous component matching.
Rocket Ride -- I can't really comment much here as I have little to no knowledge of this brand. From what little I do have I see them being more of a BJ tweak on someone elses design. Kind of cool but some part of me feels that a design from the ground up by BJ would offer something more than a tweaked existing design. I could be wrong though as I have no experience with any of their pedals.
Overall I'd say that BJF, BF and MP are all the same family with RR falling somewhere outside. Maybe a second cousin or something. BJF and BF, well they're clearly brothers. BF the little bro. And MP is like the half sister that moved to another state.
Glad to see you are trying to keep a pulse on your customer base. Doing so will surely make the BearFoot brand a huge hit. Can't wait to get my new BF HBOD