So I finally knuckled under and got an L-Bracket for my 5DII. Thanks to my friends at POTN I was referred over to the folks at Really Right Stuff who make some fantastic products.
You might be wondering what the purpose of an L-Bracket is. Its a good question. But also a very simple one to ask. An L-Bracket is designed to keep you lens over the center of the tripod head regardless of shooting in Landscape or portrait mode. The prevents the camera from hanging off the side of the head, creating more stress on the head and most importantly prevents the aspect of the shot from changing. In one simple change you are able to move the camera from one orientation to the other and still have things line up. If you want a nice review of the L-Bracket advantage go check out this link at Really Right Stuff.
On to what I got...
I decided to use the L-Bracket on my 5DII only as my 40D is for sports and I don't currently have a pressing need for an L-Bracket. Since I always shoot with a grip I got the BGE6-L model which places the bracket comfortably on the camera with the grip attached. Below are a couple pictures of the bracket on the camera. (Note: I took pics myself, but the below from RRS are much better so I'm linking over to them. Thanks RRS!)
As you can see it fits very nicely. I was skeptical getting a bracket as I thought the size and weight would be an issue. Its not! This thing is light and I really don't notice it when shooting. I'm trying to leave it on all the time so I don't have to worry about putting it on when needed. Also, it attaches with a screw on the bottom which would make it a bit tough putting on in a pinch, so leaving it on has benefits.
Now there is one caveat to getting an L-Bracket, you'll need a clamp on your tripod head which can hold an Arca-Swiss type plate. As I use a Manfrotto 488RC2 I needed to make a change as the plate would not work. I ended up getting the RRS B2 LR II which is designed for the Arca type clamps. In the end all I had to do what replace the Manfrotto plate with teh B2 LR II and I was good to go. (Note: If you have a 488RC2 the Manfrotto clamp will be hard to get off as they use locktight on it. Just heat the clamp with a hair dryer to soften the locktight and it will come off easy enough.) Below is a picture of the B2 LR II on my 488.
In the end this setup works fantastic. The 5DII is a dream to mount with the L-Bracket and the clamp is much easier to use than the Manfrotto, I'm very glad I made the change. Let me know if you have any questions on this, I'd be glad to help out where I can.