Panning, unipod or not?

I'm looking to bring my camera to a race for the first time in a couple of weeks. I'll be using Canon's 100-400L IS which has that second stabilizer mode that is intended for panning. The quesiton is, would I be more successful capturing panned images by handholding or using a monopod?

I bought a monopod and have yet to use it actually. My panning seems to be going well without it. I will have to force myself to try it next time.

I find panning handheld is a lot easier.. not sure about with the old dust trombone though, how much does it weigh?

I can pan all day with my Canon 70-200f4, simply because it is made from bumblebee wings and not middle-earth magnesium alloy..

I find that panning is easier handheld. I have never used the 100-400 but have panned with the 300mm prime handheld on my 40d with a 1.4TC. I do use a monopod for head on shots. I also used it when I rented the 500mm. So I would say the the 100-400 you shouldn't need a monopod to pan.

I really dislike trying to pan with a monopod -- it restricts the natural arc because the fulcrum (if that's the right term) is not under the camera but somewhere under your feet. Panning tends to entail a sort of swing. The 100-400mm is the heaviest lens that I have used and it's about at my comfortable limit for all-day carrying, but I would much rather have a workout than poor panning shots!

I use a mono pod, but I wedge the foot of the pod on top of my belt buckel. This allows me to pan smoothly and still keep the camera steady.

Great idea, stuman. I simply put the foot betwen my feet, or on top of one shoe, so it spins with me. No reason it has to go straight down. But it also depends on how you are paning, and how the subject is moveing. All if it comes togather so you have to adjust for every instance. Its not a single technique.

A monopod is great if you're using a 10 pound lens all day, but I wouldn't use one with the 100-400. Read the book & be sure to use the right IS mode for panning.

There are some good links in here:
Advice needed for Rally shooting

Depends where on track. On Road Atlanta coming out of the esses you have to pan up and to the right. Monopod no good.

Pan around turn 6 and 7 you could do it.

Head on as said it works great

I tried and tried to get consistant pans with a monopod in place, thinking that might elinminate one axis of unwanted motion. I got mixed results. now I pan without a monopod, and guess what- mixed results. I think for consistencies sake I will consistently work without one from now on, unless I change my mind.

handheld for panning.

I use a monopod for other shots, but not for panning

I shoot with a monopod for on-road with a big lens and handheld with a 70-200mm f/2.8.

And when I shoot off-road a monopod is almost useless, you can't pan horizontally when your subject is moving vertically through the air too.