What about losing inbody shake reduction? I don't think the Nikon wil have that. I love screwing a 1950 Helios on my K5 and having shake reduction with it. If you want stabilization with Nikon, it will have to be in the lens. So, you'll definetely lose stabilization for MF glass. I would hate to lose my SR, I wouldn't be able to use my Vivitar 800mm F8.0 handheld any more. How many 800mm lenses are there for Nikon with stabilization?
And, I don't know if it's important to you, but you'll lose the exclusiveness of Pentax. Comparing cameras to cars: you will be driving a Ford and no longer a Audi. Don't get me wrong, nothing wrong with Ford of course... But you won't stand out in the crowd any more.
Last edited by Clavius; 07-22-2011 at 02:56 AM.