I'm trying to decide between an RS-2 and a M1-S. Mostly I'll be doing multi-row panoramas with my Olympus OM-D E-M5 micro-4/3s camera, but I've got the Samyang fisheye to play with some VR panoramas as well.

I think that just adding an upper rail to the RS-2 makes it "somewhat" equivalent to a M1-S, and it would save me $100+ US. It would also allow me to start out with just the RS-2 and a lens ring for my Samyang fisheye, and then purchase the upper rail later.

I'd appreciate any feedback to help me decide, especially answers to the following:
  • What is the length of the lower rail portion of the RS-2? I haven't seen specs on that.
  • I believe that the RS-2 has a smaller footprint than the M1-S. Is that very important when doing spherical panoramas, or is that something that just makes it nicer, but isn't a critical difference?
  • Does the RS-2 take any of the rotators that work with the NN4, or does it take the ones that work with the RS-1?
  • For a small micro-4/3s camera and the associated small lenses, would the M1-S give me any necessary better stability? Or would the RS-2 be sufficient for what I want?
  • I would like to be able to carry everything on short (1-2 hour) hikes. I think that the M1-S would come apart & get put back together quickly and so would be easy to throw in a day pack. Would there be any problem throwing the RS-2 in a day pack (I'm assuming that the vertical rail doesn't come off the lower rail easily, but maybe I'm wrong?)

Thanks for any help!

ps: In some ways I'd love the M1-S, but I'm not sure I can justify the extra $100+ if the RS-2 is an adequate solution for me. I'm just an enthusiast, so things don't have to be as perfect as they would for a professional trying to make money off sales.