I can vacuum holding a cup of coffee: When I was young, my mom would smoke a cigarette and vacuum. I am sure that many moms did that since smoking was not considered a bad thing. Whether it is an upright or canister, I have had them. Right now I am using Miele, both an upright and canister. A long time ago I fell for the Oreck mailing and ordered their upright. It never seemed to clean my carpets well, especially with the dog hair I have from my 2 Yellow Labs. When I brought it in to see if anything was wrong, I was told that it was working fine but needed these tablets which go inside a small pouch in the cover to make it smell better...because I had dogs. I ended up a nice smelling vacuum but the machine still didn't do a good job.
Onto Miele. Yes they are expensive but I don't have any issues with them. I found a very nice site to buy these from, witbeckvacuums.com. I have actually spoken to the same person each time I have called. Most of these brand name items aren't discounted but somehow the person at witbeckvacuums.com threw in an extra box or two of vacuum bags. Maybe it was because I had purchased from him before, or maybe it was the fact that I asked for something to help make me feel better about spending the money. Don't really remember, but nothing should stop you from asking for anything. All they can do is say "no." And this site also ships boxes of vacuum bags for free.