Wow this looks really good especially for the price, looks like Tamron have gone for Sigma's approach with the pricing, just as Canon begins to push prices even higher these two are surprising everyone with prices that are even lower than before!
I could really be interested in this lens to replace my 70-300mm L which I only own because I got sick of trying to find a decent copy of the 10-400mm L
I like my 70-300mm a lot and it was fantastic on the first copy but I do yearn for more reach. The recent samples from the Tamron are better than anything I ever got from the 100-400mm after trying 5+ samples both new and used! This lens looks like it would give me better IQ and an extra 200mm reach! I doubt if it will be as good as the 70-300mm IQ wise though, it's a really good lens and a bit underrated by some.