A D3 isn't heavy.....try lugging around a 10x8 large plate Linhof around with a tripod looking more like an over grown car trolley jack...because your tutor "wants it pure" (kinda put me off landscaping)..
I will quite happily sling a much older (but a similar weight and size) D1h (or F5 for that matter), one fitted with 80-200 2.8 and the other with 300 2.8 over each shoulder...size and weights are only perceptions...which is what I kept telling myself walking around in the heat recently!
I'd echo exactly what Stephen posted RE; fx vs dx formats.
Andy, definately ditch your dx gear. It's nothing to do with Mike getting the D300 as a pressy or if I can bagsie the D2h
