Thanks Pig9R, I didn't find the stock seat uncomfortable on the two short rides I've had on a Rocket, however my wife didn't find the pillion too comfy and a lot of folk on the forums complain about the stock seat. The Classic seat looks far more comfortable, and a better shape for more support at the base of the spine.
The stock RIII in the UK is £400/$750 less than the Classic, but that is what you could expect to pay just for say a two-tone paint option and change of bars.
When I worked out the cost of the chrome cyclinder head, running boards, end caps, and imrpoved dual seat we're suddenly talking £,1,182, or the best part of $2,000, which makes it seem a relative bargain - assuming you would, in an ideal world, add these features to a stock bike anyway.
I did the factory tour on Monday and they were making 10 stock R3's and 48 Classic's on that day; so others must think the same, even allowing for 'new' model novalty.
I'm pretty sure I'm going to order a Classic. I like the white/red, but my wife prefers the red/black. I'll probably end up with red/black - anything for a quiet life!