I was very pleased to read your re-reply, as I've been running Windows 8 Pro for a few weeks now and have been pleased for the most part. I've read comments from a lot people talking about how drastically new and clunky the 8 interface is. I didn't find it to be so. Once I understood how the new context menu functioned, it made sense to swipe to top right to find settings. Just like anything else though, I found it took time to get used to it, and now use it as quickly as I could alt-tab a month ago.
Performance increases have been noticeable. I run a laptop, most of the time in low power mode, and 8 seems to perform at least as fast as 7 in balanced, or high performance mode. Applications and apps load quickly and without hiccoughs. My boot times haven't been in the single digit realm as some people have seen, but it is faster than 7 is. Most importantly, the memory usage seems to be significantly less than 7.
All of these are welcome improvements,
In a fluffier reality, 8 really does reimagine PC interaction. Others have drawn parallels to tablets with 8's ability to function in full screen free of distractions, but that misses an important element of tablets and smartphones. 8 is of that same lineage because it too blurs the line between local and internet. For instance, using the new start menu, you can easily use the same search bar to search for photos of your cat, or photos of others' cats on google. 8 also has great integration with email, messaging, and social sites. You can keep up to date with the non-intrusive notifications or ignore them.
The nicest feature though is that the start menu can function like a heads up display, allowing you to quickly survey your apps for anything important. These aesthetic improvements don't terribly increase productivity, but they make for an enjoyable experience much akin to using a favorite socket set or screwdriver.
I hope that others can give 8 a try and see the benefits it has to offer. There is fairly little to sacrifice or compromise on.