I'm an Apple user, and a Linux user, and an iOS and Android user. I used to develop for the Microsoft platform. I don't think I have any strong bias. However, the pros of Apple computers is their power management, Retina support, and open source dev tools and libraries. Of the three main desktop OSes, I find OS X's power management to be the only one that actually works well. You can close the lid on a your laptop, come back in 2 weeks, open the lid, and there's still plenty of juice left, and there's no wake from hibernate. It's wake from sleep.
Retina support on OS X is still far ahead of Windows and Linux. Since Apple formally supported Retina 5 years ago, and the standard resolution hasn't changed, it's been easier for app writers to support Retina. This isn't the case on Windows and Linux. Even apps like Java UIs that runs well on OS X retina are unusable on the other OSes.
One reason OS X has gain popularity is the open source support. Open source usually means Linux, and Macs provide a Linux environment with a plethora of tools and apps.
Today, I do not own any personal Macs. I have a work MBP and have a Dell precision laptop with Ubuntu as my personal machine. I'm currently on a Linux binge because I'm just looking for a different user experience. For the OP, I would make this recommendation. SP4 is great hardware, but base your decision on your specific usage. Is power management important? If it is, then SP4 might not be the ideal platform. If you want a tablet experience, I can tell you that it's not optimized for that. A tablet experience and a desktop experience is quite different. If you're using FB app on your tablet, don't expect the same experience. You'll end up using a web browser on Windows to connect to FB. The same goes for media consumption. That's fine, but it's also a lot slower than custom written tablet apps. I had the SP4 for about 3 weeks, and it was the power management that eventually forced me to return it. It's best not to get enamored with any one specific hardware device, esp one that's new. I chose the one that fits my usage, regardless of OS and hardware. Since I use desktop OSes for software development and photoshop, I don't really care about what else it can do. I use real tablets for real tablet experience. I've learned my lesson with trying to combine both. They just don't mix... yet. Maybe one day there will be more consumption apps for Windows or devtools and photoshop for iPad, but as it stands today, they're separate worlds.