I have tried to give season 7 a chance a fair few times and it has never been able to quite live up to what it claims to be doing. It tries to do too much, brings in too many new characters, for my liking, with all the potentials, and that takes away from the core scooby closeness. It then creates a bad guy, supposedly badder than any other with the first evil and uber vampires. And returns to a simplistic formula of we're the good guys, lets kill the bad guy plot. After all the intricate and complicated things they had done with the characters emotions in season 6 this felt like a step backwards to me. The priest bad guy was a good storyline and that worked well, I would liked to have seen that be more central to more of the series personally. Rather than faceless bad guys like a big nest of uber-vamps. It just lacked a personal touch, and turned it into an impersonal war, rather than a personal battle.
There is still a lot to like along the way. And some things you wouldn't want to have missed out on as a Buffy fan. The storyteller episode is nicely done and the episode about Anya's history is an important addition. And there is the episode him, which I think is a comedy classic, one of the best funny episodes. There are plenty others also to get your teeth into. The main thing is to go into it with an open mind, then atleast you can know you have given it a good chance. Maybe that was my mistake first time round watching it, my mind was closed to some of the changes, and I was settled on the ending of season 6.