So, I'm having a bit of a conundrum. I own a GH3, but I am currently on the fence about upgrading to an A7rii this week. I JUST bought the Metabones M43 to EF adapter to use with my Sigma 18-35, but I am considering returning it for the E Mount Adapter, instead. Which adapter do you guys foresee as being more future proof? It's a 650 dollar investment, so, I want to make the RIGHT decision.