I think I like the idea of Sleeper far more than the execution. It's a neat enough idea that could have been used to make something really original, but instead I don't feel like our plot was fully fleshed out.

Instead the effects feel a bit corny with the arm thing and bad CGI morphing effects. The choice to focus on one woman in particular is okay in and of itself but it winds up taking a lot of tension out of Sleeper, rather than giving us a great new perspective or something different from other content like Random Shoes. Finally, the episode's ending, while somewhat well done, felt a little unsatisfying and forgettable to me. So it's not a terrible episode - miles above Torchwood's worst, it also doesn't feel exceptional to me. Which is a shame, because I feel it really could have been something more substantial.