I think the new series is great =) Christopher Ecclestone is a great actor and although I wasn't sure if he was a good choice I think he really makes the show. There's been a lot of variety in the storylines so far and it's good fun telly xD I can't blame him for quitting after one series though, he is a famous actor and much in demand so it makes sense that he wouldn't want to get typecast (seen much of the other doctors lately? Little Britain doesn't count
). Miss Piper is also a pretty good actress, I liked that Canterbury Tales thing she was in which was what got her this job too I believe. Better than the other Dr Who assistants that I can remember.
The special effects have seemed alright for me, only been a couple of occasions where I've notcied them being patchy (fire in first episode being a prime example). If there are any other huge sfx blunders then I'm just not noticing them because it's Doctor Who I guess
Can't blame the beeb too much when they made Walking With Dinosaurs =)