I got my Surface this morning, and after playing with it for a little while, my reaction is decidedly mixed.
I clearly need to learn more about Windows 8. I'm a Windows user from way back, and Windows 8 is the most dramatic update ever. Users will either love it or hate it, and I suspect that many of those who hate it are in reality not willing to invest the time to learn the new interface. A coworker who is much better at Windows 8 than I am raved about the Surface user experience.
Running Office apps like Word, Excel, and Powerpoint is brilliant. Other tablets and OSs have ways of working with Office docs, but you really can't beat the real thing. I have users who live and breathe Excel, and nothing less is acceptable.
I am running into a few hardware issues that I'm not sure are my problems, or endemic to the Surface. The wireless drops now and then, and sometimes the keyboard will stop working. If these problems persist I'll take it to the Microsoft Store and see if they can troubleshoot or fix or exchange it.
How is the battery life? I also read that the ARM processor tends to get a bit overworked if you have multiple processes running at once. Have you noticed any slowdown?