Jason Snell writing at Macworld has a good compare-and-contrast take on the different approaches to the Surface and iPad:
I remember watching Microsoft preview the new design language at the D9 conference in 2011. And as Steven Sinofsky of Microsoft showed it off, I kept thinking to myself: “Wow, look at Microsoft. They’re going for it. This is a serious competitor to the iPad.” It didn’t try to rip off iOS, like Android was doing back then—it was its own thing, with innovative features like Live Tiles. […]
It was a heartbreaking moment when they revealed the classic Windows desktop hiding behind Metro, and a painfully familiar Microsoft Excel running on it. Seriously, was one of the most deflating moments I have ever experienced in a tech demo. Microsoft invented an entire new way to think about using its devices. Microsoft! I had seen what happened when Microsoft realized the internet was important—the entire company shifted gears and within a couple of years they dominated.
Microsoft’s approach has been to cram the entire Windows OS into a tablet and add some touch and stylus support on top. Apple’s approach has been to take an OS made for a phone and blow it up to tablet sized, then add-on desktop-type features over time.
Neither approach is wrong, but Microsoft’s approach brings with it decades of legacy bugs and horrible system crutches like the Windows Registry, but in exchange you also get Excel. When Apple moved OS X onto the iPhone, they brought with it the essentials and left the rest behind, but everything has to be rebuilt. The advantage to rebuilding, though, is having the opportunity to re-think a feature before adding it.
While I’m partial to Apple’s approach on the idea of rebuilding, it takes a long time to rebuild. The iPad still lacks a file system, and multitasking is a mess. Ten years in and we’re still rebuilding. Snell makes the argument that Apple and Microsoft are getting closer to a convergence of the two designs, and I think he’s right. And I think Apple is serious about building the iPad into the device that will replace your desktop, your laptop, your legacy OS device. It’ll take a while longer — we’re not there yet! — but the tablet will be what we use at home, and the traditional PC — with its static white mouse pointer — will be what we use at the office.