In terms of performance, I thought the DC40 and DC41 were the best of the lot. I also thought the filter setup was a vast improvement. I had a few issues with design and build quality though.
DC40 amd DC41 are the best upright Dyson have come out with
The Dc07 is a much better performing machine. Dc41 is a less powerful machine in my opinion. It has less suction, a more complex design, the brushbar is the same stiffness as the Helix Brushbars, but its round so you don't get that "sweeping" action. Overall, the DC41 may be stylish and powerful, but it's just just a bit of a step down from the DC07.
"Dc41 is a pile of plasticy rubbish in my opinion."
Ummmm, no Tayyab. While you have a right state your opinion, if you state it in a way that causes bickering and/or fighting you will be banned. I'm so done with the constant bickering from a tiny percentage of the membership here. I have my arms up and ready to wave the banning spell again.
So you've got 6 hours to edit your post, so you better click on edit and make it sound less offensive or you will be on a 7-day posting ban as well.
I have found the DC40/41 to have greater suction at the cleaner head and the brushes on the roller are a Very close together which means greater pet hair and lint removal and they agitate far better. All be it more flimsy.
I second what Alex said about the 40 & 41. Far greater agitation going on than any other Dyson upright on the UK market, despite the flimsier build quality. Do I think it's the best Dyson? No. But I think it's the best performing.