Thinking of buying this one. Has anyone used it and any comments?

You have probably seen it but good review of it here http://www.nikonians.org/html/resources/non-nikon_articles/phoenix/100f35-2.html

One possible drawback apart from it's construction might be the 1:2 magnification. You only get 1:1 with an adapter lens.
Brian v.

Thanks, had not seen that review.