I had the pleasure of trying one out and using it this afternoon, - it's in the UK shops folks! LCE pricing it at £1170. It was about the same size roughly as my old Canon 100-400 L lens, the weight was much as I expected it to be, - considerable heavier than my current 400 f5.6L, but not a problem, I hand-held it on a 7D to take a number of shots, it felt nicely balanced and the IS worked well. It focused very swiftly without hunting despite fading light. In short, I want one! But here's the dilemma. I've been told that if I use it on a F/F body the images might be soft at the edges. Someone else said there could be distortion at the edges of the images used on a F/F. Both advised that being an independent brand it might be better to use it on a crop body, despite perhaps, a lower IQ and/or more noise from a cropped sensor. Even more disappointing was the advice to go for the proprietary brand equivalent-range lens on a crop body rather than risk the Tamron, - and this from a sales rep. who was going to be selling it! Whilst I could happily accept the advice to go for the crop body, (if I was really to gain from that, - greater reach but more noise or lower ISO ceiling as against possible soft edges or distortion using a F/F body), being advised that the manufacturers' own lens would be a better bet in respect of IQ (at double the cost) deflated me somewhat, given the hype been given to this lens, and the affordable price. And the sales reps. advising me hadn't tried it for themselves of course. Indeed they might not have personally tried similar long lenses on both crop and F/F bodies to be able to justify their contention. Would be interested in other's ideas on this, before I commit!