Now however, thanks to a few shots from a certain Mr P. Reoch, I am wavering over the topic again. After looking at my RIAT photos, I decided that I should save up to buy a decent L lens for next year. The 100-400mm is still a candidate, but the 400mm f/5.6 L USM is another option. I already shoot with a 70-300mm IS USM, but the pictures are nowhere near as good as I would like them to be. Also, the 150-500mm Sigma lens - is it worth the money? I've never been a fan of Sigma lenses, I personally think the IQ is not as good as the Canon lenses.
The question is this - which one? If anyone has any horror stories or advice, please share them. It will give me an idea of a budget too.
Cheers,
Jack.

It can get a little hard sometimes when you are 20 metres behind everyone else and trying to get good shot. For Airshows I find that it is very hard to get any shots of formation flying.
