Yeah, the 55-200mm was one of the most surprising things I've ever bought. I thought it was a steal for $250 because of how sharp it was (as others have said, it is best on bright days), and now that it's typically $150, it's train robbery.
I have the 55-200mm With my D5100. It is great as long as you remember to shoot fast enough. I rarely shoot below 1/250sec and get great shots with it.
I have this lens and I like it too... Its cheap , very cheap and I have been impressed and I really love the light weight I have better telephoto lens's but I do like this one
I just purchased a refurb unit of this lens on Amazon for under $75.00, to go with the D5100 I bought a little over a month ago. I've been using the 18-55 and having a blast with it, so I'm pretty fired up to start shooting with the 55-200 as well.
I just sold my 55-200mm ED VR lens as I was generally unhappy with it. It was sharp at most apertures and most focal lengths in good light and at lower ISO on my D90.
Open it wide and full zoom kind of killed its sharpness though, particularly in lower light conditions. May have been nothing wrong with the lens but what I used it for did not work well for me.