I had a Mk1 Nikko that was very good. Easily see bits of thread on strings at 55 yards wtih good clarity and range found extremely well. Unfortunately now broke. I also have a MK3 - mine is no where near as clear as the Mk1 but ranges to within 4ft on targets out to 55 yards - the image is nothing like as clear as the Mk1.
I now have a scope from Highlands via BAR as a replacement for the Mk1. Will let you know what it is like.
My overall opinion, is that some Nikkos seem very good, some OK and some not very good. I suppose that applies to many goods.