I remember the very first year it was offered. I had no idea it was going on, we had initially booked to stay offsite as we usually did. I booked near the end of the booking window and got the hotel we wanted, plus most of the ADRs we wanted. The only dining we didn't get were CRT and WC (we had to take a really late supper at WC and weren't able to get CRT at all).
Last year we booked, based on the previous years school calendar and then it turned out to be a week later that the kids had a break. So we cancelled, sadly. This year we're homeschooling, so we booked the first week in Sept, was on hold this morning for over an hour but got the hotel we chose, and already had ADRs from last week.
I do remember though, even the first year we went, when we'd walk in to a restaurant to check in for our ADRs, lots of people would walk in for a seat (without ADRs) and be turned away.....it was sad. I think if the dining plan is going to be a stable thing at Disney, they need to look at adding more TS restaurants or something. Or maybe putting a notice on the tickets about making dining ressies early for those that don't stay on site?
I actually like the ADRs breaking up our days at the park. We plan it around parades and other things we want to do, but without the TS I'd probably run my family ragged. I get in a go go go mood and the dining allows us time to refuel when we'd otherwise just grab a snack and keep going.