Julian the 300mm was attached to my D3, using it on the end of a Fuji body would have been a laugh, tbh I find bigger lenses on the X pro or the Xt a bit cumbersome really, would love a nice small 135 f2> I have a
nice Zuiko 100mm f2.0 which is really nice, must get out and use it more on the Fuji's its the right size and weight.