Thanks for the comments, guys.

The D7100 allows a 5 shot bracket, the D600 only 3 shot, not sufficient for the HDR brackets I like to shoot. I'm familiar with in camera and in lens autofocus. I'm interested in users overall experience and satisfaction(or not) with the Sony cameras. If I stay with Nikon, I'll upgrade to the D750 or D810. Changing is expensive due to lens investment. Attachment conversions for Nikon to Sony is not desirable for me due to function loss.

I'm shooting wildlife/nature with the D7100 and D600, unsatisfied with the D600 features. I shot with the Maxxum for about twenty years before they sold out and now the size and weight of the new Sonys is appealing. No, I only have one Minolta lens, the 35-105. Opinions pro or con? Thanks.

I have tried to use Nikon's wifi accessory unit with my D600 and an iphone, but no success. If anyone has used it successfully, I could use some tips on getting it to work.
Thanks

There is a rubber gasket-like ring glued to the front of the lens. This must be removed. Behind are some screws with a retaining ring. Remove them and the lens element easily unscrews. No, I don't recommend doing it, but the rubber ring had previously been loosened in having a smashed UV filter removed. Fortunately only jamming the filter ring. Better to lose the filter than the lens.
The version II lens is tighter and they seem to have corrected the problem.

The Nikon 18-200 does not have weather seal rings in the extension tubes. I dusty conditions, such as southwestern US shooting, I discovered a coating of dust had visibly collected on the backside of the front element. I found I could unscrew the front element, clean the area and the problem was gone. Not something I'd do with a pro-priced lens, but effective. The original version also suffers from"lens creep" while carrying it. Otherwise a pretty nice general purpose lens.

Thanks, we'll be resting lenses on bean bags in safari trucks.

Preparing for my first photo safari to Africa and would like advice on long lens choice to use on a Nikon D7100. The choice is between renting a 500 f4 or use the new 80-400(which I plan to buy anyhow). Yes, I'll have a D600 with me also. Also have the TC1.4 and TC2.0 converters. Thanks.

After a western trip, I discovered a dust layer on the back side of the front glass on my Nikon 18-200 lens.It was visible in sunlight. I knew its not a dust sealed lens and didn't want to pay Nikon's service charge. It's not a "pro" lens, so I took it on. It was actually quite simple. A glued on thin rubber ring had to be peeled of, revealing about 5 screws. After the screws were removed the front lens element easily unscrewed for cleaning along with the front interior. I don't recommend going any deeper to aperture and focus elements which would probably lead to a service expense. No problems after that.