I'm not saying the duo is a total piece of rubbish, I just think if you can afford the floormac get that because it's a multi use machine as well. I have a duo and it maybe comes out every few months for something like a rug etc.
Keep checking eBay for floormacs, they do come up rarely, i found two ex demos about 5 month ago in perfect condition and they only wanted £105 including delivery, couldn't believe it. Wish I had bought both now, and it came with drive pad and brush.
Regarding the victor, there is a recent thread with lots of info on. I have the 15", but find it too big for domestics, but others say its fine, I now have a 11" one purchased this week, seems perfect for domestic. There a loads of victors on eBay, just keep an eye open. I use the 15" for commercial as it cuts down on time. Plus they are work horses, I've heard people say they have had the same one for over 20 years.