Here's an update, as of today.
To begin, the tablet was a total hit as a Christmas gift, and all four of us love it and use it constantly. The girls use it just as they would an iPad for games and taking pictures and videos. We can also use it for work, as it comes with Microsoft Office and a built-in kickstand to hold it up. I purchased the type cover as well, which is a click-in keyboard also conveniently doing double-duty as a cover when you fold it up.
So you get the idea that product quality is not at all in question.
Customer service, however...
I returned the second tablet (which was sent to me in error) on December 12th, and as of January 2nd, the amount was not yet credited to my Visa. My next step was going straight to Visa themselves, and they began the process of disputing the charges, which means that they credited the money back to me while they investigate.
I let Microsoft know about this, and was told that once the dispute process has begun, there's nothing else they can do. I disagreed, and said that they still had not yet done anything to compensate me for the ridiculous waste of my time. (This is very much not like me, which tells you how incredibly frustrating the experience has been.)
So, after more time passed, I was sent a $50 code to use towards another online purchase (not valid in-store). I don't know what I was expecting, but trying to make me feel better by allowing me to once again shop online with them didn't exactly do the trick. However, they did make an effort (they could have done nothing), so I went online and chose a $34.99 case to use for the Surface. I went through all the steps and at the end was told that the code was not valid. I'm not kidding.
A couple of days and e-mails later, I was sent a new code (this one had a "CAN" instead of a "US" in it, which I assume was the problem) and the order went through. Three days later, the case was sitting on my front step.
A happy ending? I guess so...(she typed halfheartedly)...