Some people do get restriction their first fill. I've even heard of the odd 1 or 2 who don't even need the fill, just having the band was enough.
My first fill was a bit of a horror story. I'm not going to go into details as I dont want to scare anyone. I got a really good restriction with it, but that's gone now. I still can get to a point where I have to stop, usually its around the entree meal size. But I can eat anything I want and even drink fizzy drink still, no problem.
I'm going for my next fill next month, which will be 2 months after the first. Can't wait, but I'm hoping for another xray fill.