Not exactly sure if the rant is really valid though. I can run into problems-that-you'd-never-see-on-a-15-minute-test run under any operating system.
I think the point of this marketing gimmick was to break the word-of-mouth myth that Vista sucks. The myth that got tossed around was "I hear it sucks". It doesn't get into why Vista sucks or whether it even really sucks for what you do. And it makes sense that it doesn't go there because once you do, you'll realize that every OS sucks for one or another reason: hardware isn't supported, games don't work, Swiss cheese security, whatever. Marketing is all about the perception.
Now people can tell their friends "oh yeah, they had this clever experiment and it turned out Vista is actually kinda nice", with no zealotry-strings attached.
Remember when the iPhone was first announced and common people like you and me were like "wow that is so hot", without having ever touched one? That's the message that got tossed around. Never mind that the contract wasn't exactly sexy, that you could be getting hundreds of billing pages in the mail per month, or that you couldn't get a good signal depending on where you were. It was "so hot".
Anyways. There's something important about changing operating systems that people seem to ignore: changing habits is hard and annoying. Of course a lot of people go back to the old stuff while it still works for them. It's easy to fall into routine. But that's just looking at one piece of the statistical pie. A lot of people go and switch to Macs. And a lot go with Vista. In a continent with hundreds of millions of people, we can pretty much say "a lot of people this" and "a lot of people that", and chances are, we're probably right.
One point that is more specific to operating systems: adoption and compatibility. Of course 3rd party software isn't gonna run if the OS isn't supported. Of course it can fail to run even when it claims to be supported. Every programmer knows that bugs and cataclysmic turns of events happen. Scope creep, unreasonable deadlines, inept fresh-out-school barely-graduated juniors, the daily wtf, we all have stories.
All in all
I'm not going to say Vista rocks or sucks based on criteria that I can twist to bash/praise other OSes, because that's basically good ol' Microsoft-hating bandwagoning and zealotry. I'm not going to say anything based on personal experience, because opinions only amount to speculation and the only way to really make up our own minds is to go and try it ourselves.
If anyone wants to discuss the ethics of doing an "experiment" as a marketing gimmick, I think the bottom line is this: money drives the economy, programmers get paid and people can afford to spend time blogging about ethics. </opinion>