^ I don't find battery grips necessary unless you take ALOT of portraits in the vertical orientation. As far as the extra battery life and what not, not worth it. Single battery lasts me more than long enough and swapping batteries is no big deal to me. Also the grip + body feels nothing like the unibody/grip on the 1d, so doesn't matter much there either.
I have the grip for the 5dii but not my 40D.
Ok, that's EXACTLY what I wanted to hear. Not worth it

I can't believe that you are the same guy that was debating getting a XSi or a 40D.
And here we are months later and you're going for a FF camera!
Oh gosh, I hope I'm not going FF soon! I can't justify buying high $ equipment if it's just a hobby of mine.
I have all I need for now. a wide angle/general walk around (Tamron 17-50), prime lens for portrait/lowlight/shallow DoF (Sigma 50 1.4), telephoto zoom (70-200 F4L), 430ex speedlite. It's going to be extremely hard to convince myself that my equipment right now is restricting to what I want to shoot.
From now, the only way I'd upgrade from my current set up is it I can make money from my photos. No more spending my disposible income (gotta keep saving up for a house!)
I'm really getting my technical skills down. I feel like my skills have increased leaps and bounds in the few months I've had my camera. Two things I realized that were the MOST important for me was: understanding the exposure triangle, and proper hand-holding techniques. The last is an INVALUABLE skill, especially in low light without a tripod. If I find the link where it illustrated various effective stances, I'll post it on here. Helped my images 10 fold.
It's actually liberating to start taking photos close to what I imagined in my head!