Don't. I'm sure even some people on this forum will buy it, and I'm also sure that manny who do will love it. Just because it's not a Mac doesn't mean it's not a great device.
It is by far the best computer with Windows I've owned. I'm also quite fond of Windows 8.1 but it makes a lot more sense on these hybrid devices like my SP2 than on a desktop, laptop or ordinary tablet.
Hardware wise the Surface 3 is the best thing on the market right now. Some people have a problem with Windows 8's interface, but the system is extremely stable. Mavericks on the other hand, has a great interface and usability but it lacks the stability of Windows (I never thought I would say this).
In terms of performance and stability I don't see a difference. The only thing on my Surface that isn't stable is the WiFi card and that's due to hardware, software (driver) or both. I just can do more with OS X because of the UNIX layer that it is build on. I need to add it to Windows and run into the problem that there simply aren't proper UNIX layers for Windows (cygwin...it's halfway there).
When it comes to the hardware the SP3 is no different than all those other ultrabooks. It is only the best thing in the hybrid market. Outside that there are way too many other devices with similar specs. It also remains to be seen if the new N-Trigg pen is as good or better than the Wacom technology used in the SP1 and SP2. It seems good when writing stuff but how about drawing stuff (where the Wacom really shined)? Same thing for the WiFi and bluetooth (those are a major headache with the SP1 and SP2).
Software-wise there still are some issues with Windows 8.x such as the Photos bug (thumbnails in the desktop environment but nothing in the ModernUI environment; was there in the very first version of Windows 8 and it is still there in the current version so not fixed for 2+ years). Apps like Mail and OneNote can occasionally lose your login but that's because they are mere front-ends to websites (the login times out). If you use a Microsoft Account this doesn't happen. For OS X you could name similar issues.
I consider the two OSs capable, but each needs to improve tremendously before I can say which one is better.
They are too different to compare on that level. If you need UNIX stuff you either go with OS X or something like Linux but no Windows. If you need Windows you go with Windows. That's it.
No it isn't. The SP1 was the game changer. The SP2 and 3 are mere iterations of the first version.
I've read mixed results, where there's not much 3rd party apps that make good use for it. I was under the impression the window apps did, is just MMC? How's office?
I don't use Office but I use LibreOffice. This one works when I disable the scaling option just for LibreOffice. What I found annoying is its lack of support for the touchscreen. I can't use my fingers to scroll in the document. You scroll the same way as with a wheel-less mouse (you drag the slider). VMware Player 6 was very very tiny, even on the external display so I disabled scaling for this one too which resolved all the problems. Vim is useless because it doesn't support scaling (tiny tiny tiny) which is why I'm using Notepad++ and SublimeText3 (2 doesn't support hires displays properly or at all).
As for built-in apps...Windows Explorer, Control Panel, Notepad, etc. are fine but anything that is loaded in the MMC like Computer Management is blurry. No way of disabling scaling there. Powershell however...major catastrophe. It starts out fine but in just a second it will shrink. It is like it is mapped 1:1 to pixels. I'm use ConEmu as an alternative to this because it does scale properly (it also enables you to use other shells, it saved me a few icons on the taskbar

). The RDP client is a big big problem too. It changed to scaling on the remote machine (it's my Win8.1 desktop at work) to the same scaling as my SP2 (which is fine) but it doesn't change it back when you disconnect or logoff (which is extremely annoying). The only way I've gotten the scaling back to normal was to reboot the machine.
Metro/Modern apps are all aware of the hires and scaling options so they work without any problems. The problems are only there on the desktop (the classic apps as Microsoft is calling them iirc).
I wish it had thunderbolt but I'm not surprised. That is turning out to be an Apple only interface and since it is from Apple (and intel), MS isn't going to rush to embrace it.
Not quite since many other manufacturers such as Gigabyte and Asus are putting it on their products (motherboards and such; they use Thunderbolt 2 btw). Apple is just 1 step ahead of them. We may get better Thunderbolt support in Windows 8 with some updates.
Btw, the Type Cover is great (except for the trackpad) and the onscreen keyboard is nice to use as well. The onscreen keyboard has the option to write something which then gets converted to text (like with the Palm devices). This works great, even in Dutch! I did enable to fullsize keyboard because it gives me all the modifier keys and the arrow keys. Also don't underestimate the convenience of a built-in kickstand! This and the pen are about the greatest features of the Surface Pros.