Canon EF 400mm f/5.6L USM

[Rotorhead]

I will be attending an upcoming airshow and was thinking about renting the Canon EF 400mm f/5.6L USM to take with me. Has anyone had any experience with this lens, and if so any advice?  I already have a 300mm f/4 L and a 70-200mm f/2.8 L Mk II as well, I was wondering if maybe these 2 would be sufficient for the longer shots and if so would I need the 400? I will be shooting it on a 1D Mk III, and a buddy will be using a 7D.

Thanks,

Dan

[SBGrad]

I shoot Nikon, but I'm gonna jump in anyway.

Instead of renting a 400, why not just rent a teleconverter?  A 1.4x gets the 300 to 410, or a 2x converter would turn your 70-200 into a 140-400 @ f/5.6.

[GTagami]

Maybe rent a 100-400 instead? You'll get the same reach but the option to zoom if the passes are inside the long end. I think it might be a better route especially if you are shooting with one body.

[Code20photog]

And, if you rent the 100-400, you can eliminate carrying 3 lenses for the day and go with just the 100-400.

[Rotorhead]

Thanks for the replies everyone.  I hadn't even thought about a teleconverter, that would sure beat luggin around that big 400!

Dan