I just started watching this show on iPlayer because it said in Doctor Who Magazine that it was good and I think it's awesome! Apparently there's one story based on an unused Sarah Jane Adventures one. I thought the Grazzlax might scare kids,and I thought the bit with the blood in episode 3 was quite dark. I thought having Brian Blessed do the villain's voice was a good move.
I think that this is definitely worthy of following up to the Sarah Jane Adventures.