I've just seen Atlantis 'Underground'. It was very good, although I wished they'd not glossed over the moral issues with supporting a WMD program. They could have been very interesting to explore, not to mention relevant.
But I thought it was good for building on the Wraith, who have been better incorporated into the mythology of the show than I expected. Yes, when they go up against a few Wraith guards, they do seem to fall like Jaffa which isn't good for building up an enemy that defeated the Ancients, but apart from that, they're pretty good.
So far, they've visited a number of worlds that have been victims of Wraith cullings and the image we get of them from that is good. We see how societies have evolved around the fear of the Wraith cullings and how they devastate all in their path like a swarm of locusts. It's builds up their aura very well.
I also think that the Wraith hive ships do have a certain style about them that is pretty cool. The area of stored souls as feeding stock was quite shocking.
I think that the series is off to a promising start.