I am excited for Windows 10, I may finally get around to installing it on my desktop machine. I originally had many of the complaints others did about Windows 8, but 8.1 fixed most of those, and now that I have a Surface Pro 3, many of the design choices make waaay more sense. I'm glad they are making the full-screen start menu an option, because it's great on tablets.
The issue with the bar isn't that it doesn't disappear, it's more of how long it takes. Like, when you go to click on an edge element, you just flick your mouse to the screen edge, which causes the bar to appear, and then you need to wait for it to go away. When trying to quickly Google something or access a tab, this can be fairly frustrating, not a big deal, but it lessens the experience.
Regardless, Windows 10 is soon. and I'm thankful for your response.