The problem with testing sundials in the trainer is that they are still broken. However, I've noticed that, in the trainer, Sundials work HOW THEY SHOULD for the AI players, which is very frustrating.
@Scaredgirl: I'd run two Arsenics if I had them. I'll try to win another from Morte. If I do manage to get another one, I'd build the deck you have above. However, with what I have now, I like my build a tad more. Also, Stolen Sundials still work for both players but, like a Dim Shield, they expire a turn earlier.