Andrew, if you're so concerned about the size of adapted lenses why not shoot with the native glass?
I *know* the internet tells you Sony's lenses suck but even the (admittedly expensive) unloved FE2470 is pretty comparable to the MORE expensive Canon 24-70mm f4. Sony made the mistake of releasing some poor quality, consumer focused lenses with the NEX cameras which got more traction with the enthusiast crowd. This birthed the "Sony can't make lenses" meme.
Now, Sony's tried the opposite tactic with the FE lineup. The primes are top rate. The zooms are not bad but despite objective measurements and testing showing them on par with top flight Canon/Nikon lenses the internet won't let go of the Sony-lens-meme. Sure if you've got canon glass, use it! I find it a bit ironic that Yoshi used a Canon 35mm f1.4 but stopped it down to f3.2. Using the FE35mm at f3.2 would have given better results in a much more compact setup.
[END RANT]
Do I wish Sony had enabled onboard 4K recording? Yes, but not as much as I wished they included an external 10-bit option. There's no good way (even with Slog2) to get 15 stops of dynamic range into an 8-bit pipe. Still quality 12 stop 1080p footage with no binning/skipping in a compact camera seems very promising.
As a side note, it would be great if Sony enabled a 1:1 pixel crop like the GH2. That would give us FF, ~S35mm, and 16mm shooting modes. Of course there would be more noise in 1:1 mode but I bet it would still be pretty clean up to ISO 3200.