I currently have a 400D with a Sigma 150-500mm OS lens. I have been saving up and will have 1500 or so to spend on gear around April next year. I'm tossing up between getting a 7D or whether I should upgrade my wildlife lens to the Canon 100-400???
I would really like things like the larger viewfinder, better autofocus in servo mode, liveview, and especially the better low light abilities of the 7D (not to mention the Auto ISO feature) as these things I find a bit of a limitation with the 400D.
My favourite type of photography is bird photography but I also really like macro wildlife and nature photography (which is where I'd really like the larger viewfinder and liveview).
I guess what I really want to know is how far short of the canon is my sigma lens and is it worth living with the short comings of the body to get the lens?
If people have a totally different option altogether please throw it in there. I know its a long time before I make the decision but I am just trying to get a better idea of what is the best option for me.