I don't think it's quite that one-sided. For a chunk of 2008, I was experimenting with different Linux distros to decide what I would use when XP Pro stops working. Vista I've seen and used, and would not allow in the house. I have Fedora, Mandriva, Debian, Mepis, Ubuntu, Slackware, SuSe and a couple of others on the "test box" here.
Setting them up and getting them to work was a long, hard job. I had to (re)learn a load of batch command language to make, configure, install etc various bits. Poking modules into the core was part of the fun. Kpackage and APT-GET and their cousins provide an impressive array of added application software, most of it easy to install - but you do get to see some very complicated "relationships" sometimes.
The resultant systems were indeed quick, and reliable. I was 90% of the way to being a Linux missionary.
Then the video card popped its clogs and a new one was fitted - of a different brand. At that point, only Fedora (of all the Linuxes) would talk to me at all. The rest gave various error messages about X-Server being deeply unhappy. I foresaw a week or two of Googling to try to find the fixes to remove the wrong video stuff and put the right stuff in. Those X-Server files are hundreds of lines long and pernickety in the extreme
Why Fedora rose above it all, I don't know. Had it not been for that, I would have thought it was me.
At that point, the Beta of Windows 7 arrived, and I installed that on a separate hard drive on the same machine that had all the Linuxes. It zapped Grub which meant I had to use a floppy to boot to Linux, but it set itself up completely, with never a Batch Command or a .make etc. It even found drivers for the various oddities I have installed on the machine. It was up and running, doing e-mail, and the basics in under an hour.
Installing MS Office 2003 and my usual software took another few hours, and I was all up and running. It even used the same mail folders etc (on separate drives) that I used with XP, so I could access my documents with either XP or Win 7.
The Linuxes do the same - the operating systems are on different virtual drives, but documents and e-mail etc all live on hdc6 so I can do the same things and read the same mail, documents, etc regardless of distro.
Then I tried to set it up to do OCR on my (very old) scanner. Win 7 opened a window with a message saying I seemed to be trying to set up OCR, and would I like it to do it for me. It did, too - downloaded a bunch of stuff and installed it with no further input from me. The resultant OCR was free, works flawlessly, and passes the documents straight into Word. No doubt someone will complain that it should pass them straight into Open Office, but since I don't have that on the machine it wouldn't help.
I've not used Linux since - nor XP Pro, neither.
My conclusion: if you are technically gifted, have plenty of patience, and like a challenge, then Linux is for you. If your computer is a tool to do a job, and the operating system isn't your hobby, then Windows 7 is very impressive. If you frequently add and remove hardware, that stacks the odds even more in favour of Win 7.
I remain very impressed with Linux - it gets better performance out of the PC than Windows, but Win 7 is very much faster and more capable than XP, so the gap is much narrower. If I were running an older PC that crawled with Windows, then Fedora would be my OS of choice.
However, I think my Linux days are over.