I've had my D40 for a year or so and love it, but now want a body with an autofocus motor. I thought I'd be able to put off this jump but the draw of a zoom lens (70-300 in particular) has made this patience aside. £450 for the AF-S compared to £100 for the AF make it a worth the move now. I haven't really considered any other criteria at this stage; what else apart from the motor should I look for? Ideally I don't want to pay over £500.