40D or 1DII as backup?

I have a 40D and a 5D. I love the 5D, it gets the lions share of the work. I've used the 40D maybe 3 times in the year since I got the 5D. I mainly do portrait and landscape stuff, or event work. But I've always been a bit of a generalist in that if I see a style or type of photography I want to to try, I do. I've kept the 40D to use as a backup for the odd wedding and just in case something happens to my main body. But I shot with both cameras at a local balloon festival a week ago and found that I have fallen out of love with the 40D.

So the question to you is this. Is there any benefit to picking up an older 1 series camera? I've heard great things about them, and the weather sealing, focus, and fps would be nice to play with in some situations, but other than the odd bit of sports shooting I probably dont really need those things.

Hey Gonzo, could you elaborate on why the 40D isn't floating your boat anymore? I traded out my 7D for a 5D and 40D combo. The idea was similar to yours, in that the 5D would do most of the work, with the 40D as a pure action body. I considered the 1Dii, but figured the live view, dust shaker, and smaller body would be nice to have. For my needs 6.5 fps is plenty fast, and I've read positive reports on the AF abilities of the 40D. Have either of these been lacking for you?

I dont know, it was more of a visceral thing than anything else. Looking through the viewfinder reminded how small and dark it was comparatively. I get good photos from it, but since I rarely use it I was thinking it might be fun to try the 1-series. But the dust shaker is a big selling point.

I have two 1D Mark II (and N) bodies and a 40D. I mostly prefer the 1D II bodies for everything. Once in a while I need live view or a smaller body (for carrying or to put on a bellows for macro work) and I'm glad to have the 40D for that plus the crop body occasionally gives me the right framing for a lens. Some days carrying both 1D II bodies is too much so it is easier to have the 40D with 17-40L as a second body than a 1D II with 24-70L. I love the integrated grip and weight of the 1D but if you aren't used to it, it can be quite heavy and big.

As long as I bring a blower with me, the lack of a dust shaker on the 1D Mark II is a non-issue.

Pros and cons for both ways. I was thinking of getting a 40D to back up my 1D2 but just came across another 1D2 for sale, hmmm