I read the the Valkyrie has freer breathing intake and exhaust, but don't know if this is true.
Ok I'm 6'5 and a 36" reach. What we I need to ride comfortable 98% 2 up. I have a set of Hondaline bags that look like they might fit. I know Ultimate is not making seats. I also know, like my Valks I will need some highway pegs right away.
I'm thinking about seriously pulling the trigger so thanks for your help because i know little.
Were I you, I would ride both. I am a big guy also and found the Valkyrie to be cramped and the bars not where I wanted them. With my F6B I added some bar pullbacks for $100 and an Ultimate seat and it is every bit as comfortable as my Interstate was. As far as power goes, the Valkyrie most likely has a small edge mostly due to the power to weight ratio. I doubt it is that significant in the real world everyday riding situation. I would be WAY more concerned with comfort than that extra small bit of power.
From a customizing standpoint, the majority of Gold Wing accessories will fit an F6B and there is no shortage of them!