The Windows Mojave Experiment

Only that people´s "perception" were based at least in part on accounts from others who had *actually* installed and *used* Vista.

OTOH, presentations ("Mojave Experiment" or else) are mostly flashy and made to foster good "perception". They are for the most part an idealized view that can be at odds with reality.

Even if those reported issues were exaggerated, Vista has been overhyped by MS, and is anything but revolutionary. Not even remotely innovative. Unless you consider visual differences (mostly) as true innovation in computing.

Perception vs reality? Right. But apparently not the one you're describing.

Not exactly. For example, I see some innovations in Vista. New "start menu" thingy is very good idea - such software, allownig for quick finding required option in start menu is quite useful. I know that such applets existed for other systems, but making it a part of user desktop is very good move.
Other things related to search (like search bar in system explorer, tagging and such) are good too. It is one of the many improvements in Vista I like.
Of course, there is nothing "innovative", "revolutionary" or "world shaking". But it is usefull. New user interface in Office 2007 is likewise usefull and ergonomic, and it is far from being revolutionary also.
But these are good points of system, even if they don't change the world.
And, of course there are bad points. Unfortunately, they ARE usually world-shaking. Stability for example. Speed also. Could any Vista - lover from M$ explain me why the same "gem install" operation on the same machine in linux gets about 30s, in Xp slightly more (about 40 - 50) and in Vista it slows down to about 1,5 minute?

I propose an other analyze of the result: the fact that people would rate Vista a lot more when they don't know it's Vista could be interpreted as:
it shows the difference between a real working OS and some product vaporware that has been marketed to you. Vista is indeed a total failure in the real world and people know it very well. But by just marketing a virtual product and highlighting non essential features you can make believe a lot of people the product is good... until they test it for real and make their mind in a more rational way...

This only shows that you can sell people anything with a good commercial. I would really be interested how the result would have been if people would get a notebook with vista to use for some days and then were asked again. I myself am only using vista as it was delivered on my notebook and I did not have any choice. My first hand experiences with XP were much better than with vista.

I couldn't find any specs for the hardware they've used in the experiment. I don't think Vista is bad 'per se' (I don't really know, because I'm a happy Ubuntu user), but its requirements are much, much higher than XP (the OS it is replacing).

For example, XP required 64Mb of RAM, and Vista requires 512Mb (8x higher). While 512Mb is below today's average (I'd say 1Gb here in Brazil), this is the *minimum* required, which means that the requirements for the system to run smoothly are way higher (say, 2Gb of RAM, and a good video card, which non-gamers may don't have).

Most critics on Vista were about how it was sluggish when people upgraded their systems. It doesn't count if you show it to them in a shiny new high-end machine. :)

So they were "shown" Vista. They didn't use Vista. Sit down with it for a few weeks. Get beyond the eye candy (which is really nice).
Watch it choke on printer drivers and listen to the hard drive thrash.
Ponder its unending appetite for memory. Then make you decision.
Vista isn't as bad as the rumors imply, but it sure as hell isn't as good as Microsoft claims. Vista is like a "fat girl with a pretty face".

Welcome in the marvelous world of FUD: rumors, whispers and rumor again. And it's demonstrated by the master of FUD: Microsoft themselves. Beautiful.