Sorry Jamie, I didn't see your comments before, I was too busy posting all the pictures, god it took ages!
I am a bagged person too, I like the idea of bagless but I think I will be sticking to bags; I do like the 90's Dyson's (so up to the DC05).
I do think Dyson's should make better brush rolls the bristles are to sparse like you said.
Beaters/beater bars do help with imbedded dirt but you don't actually need them really a vacuum with all bristles will still agitate (although not all bristle brush rolls are created equal) Take a Kirby or a Sebo, they have all bristle brush rolls and agitate very well.