I came from a 350D, so a huge step up for me. It arrived last Monday but I only managed to get outside with it yesterday. Lots to learn, but it's gonna be fun
I got the kit with the 24-105, which I've found out suffers from lens creep when hanging on my BR strap. A quick google shows this is quite common with the 24-105. I wish Canon would build a locking mechanism into them.
Have you got a link to that one? I've got a remote shutter release/timer which I used on my 350D, but it has the wrong connector for the 5D, so it'll be interesting to find out if I can simply buy an adapter of some sort...