K-zar…
I just came across this thread. I am currently on the verge of buying a Sony a7S and had the same concern about using/transcoding the XAVC-S video files in Premiere Pro (having moved to CS6 last summer after being on FCP 7 for years).
I’m curious to know which, if any, of those theories you mentioned ended up working best for you, and how you are liking the a7S.
Take care…
A. Tad Chamberlain
Festival Award-Winning Writer-Director
Emmy-Nominated Sound Mixer