I know I'm late in posting to this thread but I lost track of it. I wanted to reply because nobody seems to have expressed much enthusiasm for the APS-C sensor size.

Having to cover a smaller image circle (than 24x36) allows the lens designer to do more daring things. Lenses like Canon and Nikon's 18-200 offer small size, good image quality, relatively low cost and enormous zoom range - there is simply no equivalent in lenses covering 24x36 format

You're missing a really wide-angle lens? There are a number of very wide wide angles at about about $500. My Tamron 11-18 is very light and the quality is enough for my needs.

A 24x36 sensor brings you about an extra stop of usable speed i.e.12800 ISO instead of 6400 ISO for a D700/D300. Not the sort of thing you need every day. For me the most important advantage is that the highlights on a larger sensor burn out more gracefully than on a smaller one, but between APS-C and 24x36 the difference is not very great.

BTW Nikon has a "correction factor" of 1.5 and Canon has a "correction factor" of 1.6 and not the other way round. The Nikon sensor is slightly larger than the Canon one.