I can't imaging using Windows for anything other than the Virtual Machine I have for NoteTab -- and that's an application, after all. It can almost run well under WINE (a windows application layer for Linux) but seems happier in the VM.
I can't imagine
having to run antivirus and spyware checkers all the time, sucking up CPU and memory -- and still having IE let in the monsters. Plus, Linux hides
nothing from you, it never installs 5 things when you asked for one, it never puts anything into startup without permission, etc. In fact, there are so many ways to do whatever it is you want to do, that
that is the biggest obstacle -- learning how to learn how to use Linux.
Any version of Ubuntu can be made into a USB Live drive, there's an app in the menu called
Startup Disk Creator. (If it's not on the live cd, you can install it!) Make it "persistent" and you have what is effectively a portable system, that will determine the specs of the machine you boot to, and install drivers as appropriate.
You can't completely update such a system, though. A little bit, and depending on what you use for system space when you make the drive, you may be limited in how much you can install. But it's easy to play with and wipe and start again, so give it a shot. I think you can do it from a Live Boot CD, actually. A properly configured 8GB USB Thumbdrive would make an excellent portable system.
Calibre works
great in Linux. Anything said otherwise is FUD. Dr. Goyal develops it in Linux after all, and ports it to Mac and Windows.
EDIT: Here's
the Ubuntu page on installing Ubuntu to a pen drive, with several ways to do it. And here's
a GUI for Windows to install Linux to any USB, with Persistence.