For cons, the optical quality is really good, regardless of the focal length used and the autofocus is very fast and accurate.
Using it with GH2, it represents the equivalent of a 200-600mm in 24x36 and as such, I find it really useful, even freehand, with the stabilization function of the AFN. We must obviously hang, very stable, especially 600mm, but it is usable without stand in this case. And the quality is at the rendezvous so.
Anyway, I'm pretty satisfied with my purchase but obviously this is not a perspective that I use mainly saw the focal concerned.
