remember full frame can be both bad and good.. lets say..
you have a 200mm / 2.8.. with a camera that has a 1.6x zoom factor it will shoot ( or zoom) like a 300mm lens.. but look at the price different between lens..
cost.. ( about 650 dollars)
http://www.abesofmaine.com/viewprodu...smii&l=Froogle
300mm 2.8 over 3,000
http://www.abesofmaine.com/viewprodu...susm&l=Froogle
so if you use zoom it can be your best friend.. however if you shoot a lot of wide stuff.. it can really mess things up..