Has anyone shot with both the new Tamron SP 70-300/4-5.6 Di VC USD and the new Canon 70-300L, and can give a comparison of these two lenses? From what few reviews I can find the Tamron seems shockingly good for the price. The question is whether it's good even not considering the price; and whether the Canon is better. So far I haven't found any reviews that compare the two. Individually they both seem like excellent lenses, probably the best two available that cover that range, but which one is better and by how much?
I normally shoot with a 400mm prime, but I could use a second lens for times when that's too long, especially if it's not too heavy or expensive. The Tamron looks like a nice fit, but I had unsatisfactory results with my last Tamron lens (the 28-300 zoom) and I'd rather spend $1500 on a Canon lens I'll actually use than $500 on a lens that sits on my shelf. Of course, if I'm going to spend $1500 on a lens, then I start thinking maybe I should just pony up another $700 for the 70-200L f/2.8 IS II. Thoughts?