First, the peformance of my own lens and those of my close friends has been flawless for over two years now. Treated with the care all my lenses get but used under all sort of conditions including drizzle. I keep a small towel in my bag to dry it before closing it down. Temperatures have ranged from the highest in this dusty desert (100.4 Farenheit today) to low (26 Farenheit) without a problem. Second, I shorten AF times by using the Limit Switch. Third, the D100 is not based on the N80, although it may look that way. It has a completely different body.