I thought it was great. In fact the best part of the game and why I still say it's better than NV. Not so much the being James' son part, but growing up coddled in the vault, and then emerging into the blinding light of the mysterious wasteland. It puts you and your pc on equal footing, you both don't know what to expect, it's a scary alien world to you both, it was just downright beautiful in fact. IMO every fallout should start in a vault definitely, it's too perfect.
In NV you know your crappy backstory too, you're a lame courier who gets shot in the head by a d*****bag loser (how embarrassing). I only want one of two things- ambiguity so I can make up my own backstory (like TES), or exactly as FO3 did, start as a kid so I can forge my own story. A kid is ok because you're nothing yet. I don't want them telling me what occupation I had as an advlt. They're insisting that my character is some guy who turned out to be a working stiff, when I might not want to RP a loser.
I'm happy if every fallout you start as a vault kid, every TES you start as a mysterious stranger who has found him/herself in trouble with the law.