Re: Nikon Adapters
The cheap adapters are pretty much fine, with a few caveats. I only have the cheapest of the cheap and I'm quite satisfied. For your DX lens you can get an adapter with a ring that when rotated will press on the aperture lever on the back of the lens, thus adjusting the aperture. It's not as good as a real aperture ring, but it is better than nothing. The expensive adapters are no better in this regard.
The cheap ones can have a few problems:
1) Some have parts that can loosen over time, so you might need to tighten up a screw occasionally
2) They may not have the same precision as the expensive ones, so at wide apertures and long focal lengths you may not be able to focus to infinity, or you may end up focusing past infinity.
3) My Nikon adapter had a light leak - part of the locking mechanism let light thru it; some caulk or tape fixes that.
I don't see any of these problems justifying the absolutely astronomical price of the high end adapters.