Thanks to all the millions of threads on here about the 100-400, I finally decided to pull the trigger yesterday and just ordered it. Due to arrive on Tuesday and I can't wait to take the first shots with it 
For any UK buyers, I wholeheartedly recommend kerso: best prices in the UK, no doubt about it, and great communication throughout. And thanks to all of you guys for posting opinions on the lens, it really helped a lot.
Right now I'm pretty well covered on the focal lengths; still using the 17-55 kit lens and with the 70-300 Sigma there's not too much of a gap. But since I'm going to be getting rid of the Sigma, this will leave me with a much larger gap, especially with the 1.6 crop.
Given that Canon have got a whopping £100 rebate on the EF-S 17-85 IS (meaning i can get the lens for close to £200), I was considering getting rid of the kit lens as well and using this as a replacement, as it sounds like an ideal walkaround lens and the IS and fast AF would really help. However, I'm a bit concerned about the distortion/CA issues that have been reported. I can't afford the stretch to the 17-55 f/2.8 and that wouldn't solve my length issues anyway... any suggestions?
