I had a Vivitar Series 1 70-210mm F3.5 in a Minolta mount on my m4/3 camera(G2, which I don't own anymore), but the lens broke, and I got another camera system instead(beside the point). Today I got essentially the same lens in a Nikon mount to use on my X-E1. Physically, it's a nicer lens, and I think the glass is cleaner too, however focus is a bit harder(possible due to the larger sensor?), and IQ is meh. On my G2 the combo was really good(imho), part of why I got another one. I will do more testing and such, but could the issues I noticed on my initial test be due to the large APS-C sensor of the X-E1, a bad copy, or something else? Thank you.