Forgive me if this has been discussed before, but does the vibration reduction of a second-party VR lens work on Panasonics? That is, could you use a Canon or Nikon VR lens with an adapter and have the vibration reduction work?
Short answer on the Nikon VR end: nope, I don't think so. The Nikon body is involved in the VR feedback.
On the Canon IS end: not sure, but I would be surprised if it worked!
Not sure what the situation is with Sigma OS lenses (although none of their 4/3 lenses have OS).
I would think no, because there is nothing to permit the stabilization feature on the Canon lens to electronically communicate with the Panasonic body. I also would not use Canon EOS lenses on a mu4-3 body because no way to control aperature since so aperature ring on the lens.