First of all.. It is a very good prime lens for the price. No distortion, as sharp as a state of the art samurai katana!!!
Aperture and metering works very well... however, while shooting with 1.8D aperture especially under fluorescent light, the posometer of the D3000 may sometimes have errors on the light intensity calculations (I guess.. ) which sometimes results in +1+2 Exp (bright) photos. That's why I (almost) always compansate it with -Exp settings.
If you have a D40-60-3000-5000 entry level nikon... like me (D3000)... Think twice. I am really used to manual focusing with sharp aperture settings so... no problem! But If you never had to manually focus with 1.8D before... Practice first with ~100 photos... to get better and faster. If you want it to be snapshot, sorry... you need an AF-S....
Cheers!