I have found the hand grip hard to use with my big hands. (properly adjusted)
I have pushed the grip release button thinking i was pushing the record start stop button.
I have missed several shots unfortunately.
Does anyone else have this problem?
I feel Sony should not have any other buttons near the record start/stop button.

It is indeed awkward. I do most of my shooting on a tripod and so have invested in a Lens Controller that mounts on the tripod handle for zooming and with a rec/ret button. I use the Libec ZC-9EX but there is also a controller made by BeBob.

not so bad for me I'm 6'4" 280lbs. I keep it rotated about 45 degrees.. My fingers fall onto the zoom and rec button when in shoulder mode.

My hands I thought were average, but I have a hard time reaching the button without really trying. I've never hit the release by accident. Record is about the only button I can easily reach

Yup- not my favorite ergonomics-wise. I would recommend a shoulder support.

-Noah