I've spent a couple days now using the RT-version of the Surface and I have a few thoughts. Most of them are complaints borne out of past experiences, but overall I'd call it pretty positive.
0. Surface needs a swipe-to-type keyboard.
1. There are no decent web browsers. There's IE. But TPLs work and apparently my TPL subscriptions are stored as part of my Microsoft account login, but I'd rather have Firefox or Chrome. To my mind, that's a disincentive from using the web on this thing. I don't like having to gesture just to see the back button and address bar. Holy crap does that blow.
2. But I like the Email/Contacts/Calendar more than I thought I would. Honestly, I hate GMail's conversation view. Hate hate hate. Coming from Android and the GMail app there, the stock Email client is actually a breath of fresh air. I like how big and finger-friendly things are, something I didn't really appreciate when I was using Thunderbird on the Surface Pro.
3. The Share Charm is the biggest waste on the platform. I can't even make it useful when I try. I guess it talks to Facebook? Maybe? I can't make it do anything I actually want to share to. I did finally find a stand-alone Metro app called "Share" that provides a hook to Google Drive and Dropbox, but not to Youtube (RT famously has issues with that) or any photo-sharing services. So data sharing is still pretty minimal, which completely blows for a mobile device that doesn't have 100% data portability in the way that Android does.
4. Printing. Printing works, kinda. RT wants to connect to shared Windows printers. It does not want to talk to Printers via LPR or even HTTP, which is what decent standalone printers do. So I can print to the crappy HP inkjet in my co-worker's office but not to the big-boy Samsung, Xerox or Brother printers in the building. Also, in spite of the fact that printing is one of the few things that RT really does have in its favor, very few applications support printing aside from the Office 2013 apps.
5. Office 2013 apps. This has been said before and now I am saying it: Everything the fuck else on Surface RT is a modern-style ("Metro") app. The Office applications are more or less the only applications that run in Desktop mode. There's no accommodation for finger friendliness. You wanna scroll that tiny-ass scrollbar? I hope you have girly-fingers! Also, in spite of having multiple connections to cloud storage services installed on my device, those services are not accessible from Office unless they happen to be named "Skydrive."
I think the right strategy for living with an RT is to forget the Desktop and the Desktop apps. Use Google Drive or something. That's an ironic contrast from standard Windows 8.
6. On a related note: Windows Help is also a desktop app for some reason. Even help for Modern style apps. Gee thanks.
7. There are some weird holes in the realm of application availability. No one appears to be making a decent local media player, though there are several pretty decent streaming music clients. I hate Xbox Music, the Windows 8 stock app, but I simply can't find any other app with which to replace it. There are crap-tons of streaming music players but nothing that easily syncs Windows Media Player (or any other desktop media playback software) with the RT.
I can do most of the stuff I want to do, but a few of the services I thought would have an app-ified form (e.g. Imgur) really don't. I also thought I'd be able to find more tools to extend the Share Charm or perhaps replace the stock on-screen keyboard, but that stuff just isn't there. Maybe those things will get better after another couple years.
8. Everything in Metro-land is big and finger-friendly. They're all also a little bit information-sparse, but I can see how that would be an improvement for a lot of people, especially older sorts. I wish more apps would leave buttons on-screen, but for a device and environment made for consuming content, it's acceptable.
9. I can still *DO* essentially everything I want to do. I can open and use the files I have already (a 720p MKV with embedded subtitles played just fine). There are a lot of things that are kind of lame, but not huge, gaping functionality holes. The experience for me is analogous to sitting down at an OSX machine or being forced to use KDE after years of being an AfterStep user. The tools are there, but they're not the tools of choice.
It's not exactly what I want for myself, but I can definitely see recommending one of these guys to other people. Forget that it's "Windows" because it's not. It's CLOSE to Windows, but more importantly, the tiles and bright colors actually do work well and consistently once you wrap your brain around swiping up from the bottom or in from the right. The high contrast, large-ish print and chunky icons do a great job of making functions and options obvious, even if more than half of one's potential choices are off-screen in the Options or Charms Menus. What really makes me say this was spending a couple hours showing the RT to a 63 year old man. I saw his light bulb go on. An anecdote is not evidence, but the relative consistency of the experience and the platform makes it a lot more teachable to others, and it does NOT have the sucktastic iOS security model that prevents an iFruit from doing absolutely anything useful or interesting.