1. The trackpad hardware is great. It's so good that when we were making the Bamboo Touch at Wacom, the Macbook Pro trackpad was the standard we measured ourselves against.
2. True pixel-level scrolling from HID devices. Windows has the concept of "wheel scrolling", but it's only vertical, and lots of apps won't scroll in less than a wheel increment (which is oddly 120 units), so you're stuck with jerky 3-lines-at-a-time scrolling. Oh, and it's vertical-only; there's no system standard for horizontal scrolling.
3. It's never had a software-based rendering and compositing engine for the windowing system. The Windows team is fully committed to backward-compatibility, which means allowing all sorts of wonky GDI-based pixel pushers to work they same way they did in Win95. OSX has been OpenGL-based from the start.
I used Mac for a week and went back to Windows. The jerky scrolling in Windows was driving me crazy. The fact was that before Mac I never realized that (maybe I'm numb to perfection) but it was only using Mac that it occurred how much crap scrolling is in Windows.
There are many many quirks like this in Windows that you only notice once you use a different window manager.
OS X is quite unique in this and probably stems from the use of common menus for different windows, which also makes it uniquely inadequate for handling multiple monitors. I just can't take a WM that doesn't handle multiple monitors well seriously.
I'm sure if people were presented with both options; regain focus and lose selection vs keepi g selection, they'd choose the keep selection. It's as if someone used the computer and said "you know what would be useful?..."
2. Wheel scrolling is a feature. Yes, horizontal scrolling sucks but vertical scrolling is working as intended and something I really prefer. Yes, I'd like a good horizontal scroll but the use cases where you need it are extremely rare and often stem from bad UI design in the application - not saying that as an excuse but just that it isn't a big issue. Microsoft have tried scrolling wheels that can go horizontal as well but they were mindbogglingly bad (my opinion).
3. I don't see how that is an issue (in practice) for anything that isn't done for Win95. And if it was made for Win95 I'd rather be able to run it than not. Backwards compatibility at its best. Doesn't bother you when you don't need it but can still handle corner cases as well as can be expected.
The change in responsiveness in the UI when you're no longer using the trackpad is astonishing. It takes me longer to perform tasks on my Mac than it does on my Windows 7 platform - particularly if that task involves switching between windows in the same application. The loss of my extra mouse buttons to move backwards & forwards on web pages has been especially painful (though oddly, they work to bring up Mission Control & the Application window controls)
And frankly, after using Mintty from Cygwin, the default terminal on the Mac was pretty terrible to use. Fortunately, that was easily remedied with the use of iTerm.
I'm looking forward to the time I no longer have to use a Mac for work development.
Unlike OS X where a really good Taskbar implementation cannot exist, I can add something just like Expose to Windows. It's called Switcher and it does pretty much everything Expose does.
The Taskbar is still better though because it's always there and at a glance I can see what's running.
And, perhaps most telling, the taskbar icons don't bounce around like a 2 year-old on sugar to announce that they need your attention.
OS X is basically rigid where Windows is flexible.
Also, a new feature of Windows 7 (actually I think it first appeared in Vista) is Win-Tab. It is like alt-tab, but gives you a preview of the windows instead of their icons. If you really need to see what a window looks like while switching through your windows, that's the way to go. I don't care for it, as it's a bit laggy, but then so is Mission Control on my Macbook.
I've tried using Expose and multi desktop setups but they just add complexity to my flow. Expose looks pretty but I avoid it because it randomly lays out the thumbs in some way that has nothing to do with how I've actually arranged them. Command + tab is application based, so I can't switch between windows easily. Command + tilde does that but it works completely differently by switching windows on keydown and keypress instead of showing an overlay. I'm sure next version of the OS X will introduce a new window management tools and obscure short cuts that just adds complexity to the system. The whole thing feels like random band aid solutions built up over the last 10 years.
In my opinion, "a better Terminal" is not a strong premise when it comes to making a general case for one OS's user interface being superior to another's.
[edit] If the comparison was between bash (et al.) and Powershell, then terminal preference would seemingly be based on familiarity rather than the degree to which one can access the OS via the command line.