Brad,
I was wondering what hull you would choose if you had the choice?
To start I am posting this to all member of the group so they may also read your views.  As a person who has run the grand many times as a guide with 4 or 5 people in the boat I can see many reasons you and commercial companies choose the Briggs design.
What I was wonder was what you would choose for yourself.  After rowing and building a few boats, I like 16 footers.  Unlike many I want my boats to be as light as I can build them while keeping them solid.  I also don't like a boat which has too long of a flat spot.  For me they react too slowly.  I like a boat which spins more quickly but not so quick that a lateral hit will kick it around.  I hope to sell one of my boats at some point after my next Grand trip in a few weeks so I can build another.  
Having been around boat building all my life, I don't work completely from plans.  I use them as a starting point and then make changes with the idea of tuning the way the boat behaves to my requirements.  My plan is something like a 16 foot double ender with transom but with a little less rocker for about 6 foot near center.  Since I will add a transom dropping the bottom a bit I would curve the last 3 feet back up an inch or two to get the stern back to the original double ender line.
What do you row when you are not working?
This is really a discussion for all and I look forward to everyones input.