Mind, most of the stuff I thought on first viewing still stands: it's a horribly obvious nod to The Poseidon Adventure (which incidentally reminds me of Richard E Grant's novel 'By Design'- the plot revolves around the making of a film billed as 'The Poseidon Adventure in space'). When first hearing about the premise I was rather hoping for something along the lines of Douglas Adams' superb Starship Titanic video game and felt disappointed when it wasn't. RTD's writing was weak in places, especially at the end (still want to reach into the tv and slap Ten, dammit) and the religious imagery is about as subtle as a punch in the face. And yet it's still better than 'The Runaway Bride', probably because in retrospect, that whole episode seemed plagued by lazy writing.
Knowing what's coming with the S4 finale now, I'm also rather bemused that RTD used a crippled evil genius (Max Capricorn) as the villain here when he was going to bring Davros back. Oh, well. Bring on Partners in Crime, and fingers crossed Donna has become as awesome as fandom's made her out to be.