I have the Butch Baldassari's "Mandolin Workshop" DVD. Its OK and he has some good suggestions for playing, especially for improv.
I have several other DVD's and I do take away something with each of them. But I have yet to find a good definitive book or DVD.
As far as a chord DVD, not sure how that works? How do you look up chord positions with a DVD? I carry a pocket size chord book in my case so I can look up some strange chord. But most BG songs really only require 3-4 closed chord positions that are movable up the neck.
Las Vegas, NV
"Every day brings a chance for you to draw in a breath, kick off your shoes and play your mandolin."