In reply to Dave Heaton:
I've just bought a Tokina 11-20mm f/2.8 which is the replacement for the11-16 and the RRP is the same.
There was no major price dip on the 11-16mm when the new lens became available as far as I could tell and the price difference between the two is not massive now.
I spent £350 at hdewcameras.
I've noticed no particular flare issues with the new lens. It's sharp and I am very happy* with it in general - just need time to get out and use it more.
Things to consider.
It's a sturdy lump to carry in the hills and takes large 82mm filters. (I believe the 11-16mm takes 77mm filters).
I'm still trying to find out if the Lee wide angle filter holder fits it before buying - some reports that the hood bayonet fitting gets in the way?
I've never met anyone that likes Tokina's push-pull MF-AF clutch mechanism (though the new one is smoother apparently).
The Tokinas don't have any sort of silent wave motor.
I'm not currently hosting any of my images in a decent online gallery and so you will have to accept the appalling quality that the fb upload & compression algorithm give you...
https://www.facebook.com/photo.php?fbid=10153299989781239&set=a.1015089...
https://www.facebook.com/photo.php?fbid=10153305263626239&set=a.1015172...
https://www.facebook.com/photo.php?fbid=10153329369871239&set=a.4226911...
https://www.facebook.com/photo.php?fbid=10153359626891239&set=a.1015089...
* Actually chuffed to bits with it.
I agonised over which lens to get for a long time - exacerbated by my difficulty in getting anywhere to try the different lenses.