What I am puzzling over now is whether it is better to have a very bent trail arm and wrist using what I believe Kelvin calls a 'drive/holding' release. I am actually trying to move towards that type of release as I have an obvious tendency to flip the hands through impact. It will be interesting to see if it makes a difference on the scorecard.
I have made a rather large change in my impact position and posture in the last few months. This as resulted in much less lower back pain. I can trace a great deal of the lower back improvement directly to your advice to keep my back in neutral or arched as I call it. I had not realized that in my efforts to suck my gut in and keep good posture I was losing that position while just standing around or walking not to mention in my golf swing. So, thanks for that!