Long ago (circa 2007) I remember having a chat with an MS PM. The guy could not comprehend Windows Vista sucked. Internally, apparently everyone loved it.
I bet that the systems that Microsoft employees used internally at the time (mid 2000s) were the ones probably best supported by Vista in terms of drivers and performance.
If you had a beefy desktop Vista actually ran very smooth. I happend to have that at the time and I did only have a fraction of the issues that Vista i famous for. Everyone at MS probably also had beefy computer that ran Vista just fine.
Long ago (circa 2007) I remember having a chat with an MS PM. The guy could not comprehend Windows Vista sucked. Internally, apparently everyone loved it.