will be a bestseller.. because only dummies will buy the 6D...
Basing on observed forum's needs there are far better books to write and sell:
"Arguing against DXO sensor results in five steps"
"Tutorial on the differences between EOS 5D2 and EOS 5D3"
"Choosing between 5D3 and D800 for dummies"
"Why Canon gear's prices are so high - guide to the world macroeconoomy"
"Reasons for selling 1Dc a few thousands dollars more than 1Dx - pocket guide"
"Canon or Nikon - Ken's mood fluctuations reasons with colorful timeline graphs insert"
"Getting more DR on your photos with the lens caps on (special offer - free scotch tape included)"