Given the recent announcement and the affordable price of a 6D with a 24-105mm kit, I'm starting to seriously consider the full benefits of a move from using a 450D with a 15-85mm to a 6D with the 24-105, specifically in terms of shooting in low light, depth of field and so on... Whilst I'm sure some will shout, buy a 5D III, but seriously folks, I'm not happy to invest that level of my cash into a camera, so... Please, given my current lens line up, consideration of keeping the 450D with the 10-22, perhaps trading my 15-85 & 18-55, what can I expect and are there any pitfalls I need to think about ?