Hi I am currently using Cannon 40D with Sigma 150/500mm , whilst as a novice I like this lens I find it too bulky to use hand held and poor in low light conditions. Apart from the name if I were to switch to the Cannon as a novice would I reap the benefits?
Also having spent over £2000 on gear I would find it very hard explaining to my wife why I needed another lens!! , can you buy gear on credit anywhere?

Thanks

Adam