I read your post early this morning Iain and was going to reply with "it's a great lens" but wanted to give you a bit more feedback.........well having thought about it all day I can only echo the positive comments above.
When I first purchased it I thought it was going to be far to big and heavy to walk around with
but having carried and used it all day at several sporting events I must say it was no trouble at all.........compared to the 300mm IS 2.8 it's small
If you make the purchase I'm sure you will not regret it mate
