Now that I have spent the past few months with Sony after leaving M43, I have decided I would like some additional reach. I really prefer native lenses vs adapting anything, especially for a telephoto zoom where I want great AF and IS. I know the two lenses are vastly different in price, but that aside, for those that have used one or both, what is your impression? I have read some people having poor quality from Sony with the 70-300 where the 100-400 reviews have been stellar so I am less concerned picking one up used. Thanks in advance for the feedback!