Proof here, with commentary from Slashdot:
From install time to GUI efficiency, Ubuntu beats Windows and is often twice as fast. Where Windows 7 is competitive, the difference is something the average user would not notice. The average GNU/Linux user is now getting better absolute performance from their computer as well as better value than the average Windows user.
Where have I heard this before? I’m running Linux Mint on my laptop these days, and it’s awesome. Compiz Fusion is really cool, and doesn’t seem to cause a performance lag. I can now use Linux with work… everythign I want to use the laptop for just works.
Totally, you can even use wine to run some stuff as if you were on Windows, if you really have to. I think it takes a little more of a power user type to do some things in Linux, but with all the on-line tutorials, it is totally doable.
I've been able to leverage ancient (in computer years) hardware quite nicely using Linux. I've got some $200.00 machines doing $800.00 machine work.
Linux, at least Ubuntu, is getting a little more "bloaty" these days, but it's still a great distro and there are lots of other light weight versions out there.