They're basically the same but better hardware support lead me to Ubuntu. This is because Ubuntu repos / installers by default include more drivers.
I use XFCE with Ubuntu for a lightweight desktop and have disabled "Ubuntu One" and some other bloatware.
If you want "least amount of cruft," which is strictly perceptual, then Debian is the way to go.
If you want Linux and you simply to get work done regardless of ideology, Ubuntu is the way to go.
Switched to Debian awhile ago and found it annoying that a lot of things online are now Ubuntu specific (guides, etc) so some small things are different. I'll probably install Ubuntu again soon.
I used Ubuntu for a few years off and on. I got fed up with Ubuntu One and some of the goings on with Ubuntu. I switched to Debian Wheezy.
Ubuntu is a bit easier to setup, for example, most printers are plug and play on Ubuntu. It takes several extra steps with CUPS to get Debian printing.
I think you'd have to weight your questions to come out with an answer. The above seem to cause a dead even decision when I go through your questions in my head.