<p>Last winter I went from a Nikon D700 to a Sony A7. I also purchased a D7000 for auto focus and tele (300mm f4 + TC) work. The Sony works fine for manual focus, a am using a Nikkor 17-35mm f2.8 and C/Y 35-70mm zooms (huge on a A7) plus primes from 28-100mm Nikkor, Canon FD and Contax-Yashica. I have purchased an adapter for each lens. Each lens is rather large and heavy but the Sony A7 body is much smaller and lighter so there is a reduction in volume and weight. When I need AF I use the D7000 other times it is the A7. Each different things well. I have yet to try a Sony or Zeiss lens and probably will not because of selection, performance or price not being a good value IMHO.</p>