...Incidentally the points that have driven me to wanting an '06+ model (bearing in mind I'm only going from what I have read) are Heat deliver to the rider, screen causing stability problems and pillion peg position. (my wife has been screwed up on the back of a Fazer to date!)
Never heard of Gen Is having screen stability issues....I've had mine up to FJR nominal speeds and no issue there.
Regarding passenger peg positions, I think knifemaker or somebody else makes modifications if you want to lower the the pillion pegs.
Regarding heat...I had an 04 that bit the dust a bit hard in Arkansas...I replaced it with another 04...no heat issues, and I've been riding in temps ranging from 17F to 100F.
However, if you want to pay more for a slower bike...go right on ahead...England is still a free country - I think.