Because you demanded it: the return of the farting aliens! And its...pretty good?
Despite his rocky introduction, Cap'n Jack seems like a fully-realized member of the TARDIS team. The charm is suddenly there, and he just seems like he belongs, somehow.
The story does a really nice job of exploring the Doctor's intent to bring Margaret/Blon back to Raxacoricofallapatorius, where she will be facing the death penalty. Annette Badland plays her perfectly, delivering an extremely charismatic performance that walks the line between camp villainy and genuine sorrow. It's a tall order for any actor, and she makes it look easy.
You know who else is pretty great? ~~Ricky~~ Mickey! Noel Clarke - scandal noted - really sells Mickey's bitterness over being left behind, and his feeble, slightly manipulative efforts to move on with his life.
It's a shame Cathy, the reporter, isn't seen again after her brief appearance. Mali Harries does a lot with a little in the role, and it would have been nice to see her again, either in this or another episode.
Now we know what staring into the heart of the TARDIS does - it turns you into an egg. I look forward to that happening again some day.
Lastly...this episode is a great little tourism ad for Cardiff, a city I knew absolutely nothing about before this show came along.