Oops - beat me to it; I was looking for that thread.....
A few things to consider about the online system; it is great because it can give you alternatives for your dining ressie, if the one you made is already full. It is something a human cannot do as quickly.
You can adjust the time as needed to see if you can find an opening. If you just feel it is all about the experience, like for me, it was the Prime Time 50's Cafe, you can keep searching until you find what you want.
In one of my cases, I tried to book CP in MK and it was completely booked. It suggested 1900 Park Faire in GF, which I would have never thought about.
It is also good if you are going at a really busy time, make your ressies in the order of importance to you - they give you a window of time to complete your ressies - for me, it took about ten minutes and I was done.
So it really is a great help!