I enjoyed it, but it's a bit too early to tell.
There's a lot of change for this series, Stephen Moffat taking over from Russell T Davies, new writers, a new companion and the new Doctor. When the last change in Doctors happened, the writers and the companion stayed the same, which eased the change for the viewers
I get the impression that they seem to be appealing to a younger audience, but maybe they always were but David Tennant's appeal attracted a slightly older crowd ,especially the ladies ;o)
Matt Smith has a huge job to follow David Tennant, who did an amazing job and is so well loved, being voted the best doctor ever!!
I think he'll do fine, but it'll take a while for everyone to settle in, and for the viewers to get used to a new doctor, it's a bit soon to start writing him and the whole series off, after just one episode.