I quite enjoyed this, though I think that was because it was reminiscent of Assignment Two from Sapphire and Steel. I thought that what was done, was done well, but I wanted more from the episode. There were more lines for Tosh, obviously, and some more for Ianto - including a nice reference to his duties (and, unlike last week, they didn't take lines from Owen and reassign them verbatim to Ianto just to even up the line count).
Would like to see more from the previous-era Torchwood teams, and in particular, I'd like to have known who wrote the messages (cf. War Without End in B5), and who sealed them. I'd like to have known what really happened to Tom. And while the drama was in Tom being faced with what was necessary, that was only according to the messages; it's possible that there might have been more to it (cf. Sahjhan's fake prophecies in Angel).