I had Tiger when Vista came out. I ran the Beta 2 and RC1. Beta 2 was so laughably horribly resource hungry I kept wondering what kind of machine Microsoft thought people would be running when Vista released.
As an example, the CPU idled at 20%.. meaning NOTHING is going on and it's running at 20%. Memory was consuming a good 1.5GB. Both of these while doing nothing but looking at the desktop.
My last MacBook Pro was my first Mac ever, and my current one is my second. For notebooks I'll never have anything other than Mac, but for my desktop, I need a PC to accommodate all the games that I have bought for PC over the years and going forward compatibility with newer titles. I dual-boot XP and Vista on my desktop for compatibility for apps and games. I figure I'll eventually be able to use Vista full-time for that desktop. It's reasonably enjoyable, but I get much farther much faster in Leopard than I do in Vista, and that's after more than 10 years of Windows-only computing.
I agree with your assertion that Vista has some deliberate Mac-like setup features... Including the use of a rendered desktop environment, transparencies, the navigation bar on the left hand side of explorer windows (not unlike the one found in the Finder). In Vista I turn that off, as I get around faster with the interactive address bar found at the top of the windows. I wish Vista's search would index more efficiently and index the whole drive. In Leopard I can find any file I want in seconds. In Vista, if I'm not searching in an indexed area, I have to specifically tell it to search in the non-indexed area.
MANY Windows users are very put off by the new interface in Office 2007. I like the new one, and I've heard why they changed it so drastically. They said that the top 10 feature requests for office every year are features that are presently possible in Office, so they decided a new interface was needed to hopefully reveal the functionality better to users. Although I like it, many users I've come into contact with do not.
So, to answer your question, yes I've used Vista, and I do like it . . . but for my very specific needs and tolerances, it's not the single answer to my computing needs equation. It does answer my gaming needs almost completely. Whatever it doesn't cover is covered by my MBP, my XP partition or my X-Box 360.