Well i just went through the same decision making process. I looked long and hard at the Champions and red and blue.
I ended up buying the Yamaha 2400isHC and I have no regrets other than I spent so much time researching them all. What won me over to the Yamaha was the 3 yr warranty parts and labor and the ability to take it to any Yamaha dealer for service if needed as well as the fuel petcock shut off. It runs my 13,500 AC no problem and it is just light enough for me to pick it up and move it by myself and it is very quiet even at full load.
The Hondas didnt offer the fuel petcock, the Champions need to be sent back for service and you pay for shipping also shorter warranty period.
Good luck with your decision I am very happy with mine.