Ive been looking at the 70-300 options that are out there and was seriously considering the Canon 70-300L, but today i started looking at the Tamron 70-300 VC and it seems to be a lens that gets decent reviews. Im just trying o figure out if the Canon is really worth $1,000 more than the Tamron. I know the Tamron is not as good, but is it 1k worse? Thoughts?