Thanks for the responses so far, everyone.
Abge, I don't need to use it for Office primarily, but sometimes when I am away from my laptop, things come up. To clarify, I wouldn't be using it as a laptop replacement, 99% of the time. But if I am traveling, either for a short or long trip, I often find my laptop too clunky or inconvenient. Also, I have similar situations to what Spyman described, that happens to me all the time, and sitting with a laptop on the couch just isn't ideal.
Ramsu, do those Office equivalents actually get the job done usefully? I do a lot of powerpoint, and I have never had a Powerpoint replacement maintain the formatting etc. I do editing that has to maintain formatting and track changes between users. I'd like to do that on the couch or on a trip without breaking out the laptop. I do like my Android phone, though.
Spyman, does the Surface use a stylus effectively? My fingers are fat and sweaty all the time.
Here is an example of two of what I would want: I have a shared office computer right now. It does not have my files or bookmarks on it, I am uncomfortable installing Dropbox on the shared computer, and using a jump drive or web interface is clunky. I'd like to be able to bring a tablet some times for the hour or so of down time I have to do a little light editing and web browsing. At a coffee shop or during a doctor's visit or whatever, it's be nice to have a computer I could just take out of my bag, use, and then put it up at a moment's notice, without fussing about a power cord or anything.
Krellin, I like those - the Lenovo Yoga is super neat - but they all seem too expensive.