at 1.8 (wide open) is sharp. By 5.6 is first class, up there within the best. I have the feeling that since the lens is cheap still doesn't get the due respect. If the cost was in the $400-500 range then maybe this gem could get better reviews (dpreview included)
in other words if we take other primes and compare none will perform better (with the only exception of the 1.4 , maybe)
Dunno what the expectations are but this lens does everything a prime used to do, only better than everything I saw in the Nikon mount so far .
better than 50 1.8D, 50 1.4D, 35 f/2, 24 and 28 2.8D.
on DX the hood is useless, better to use the hood of the 55-200 first version (fits perfectly and gives more protection)