If it was me, I'd probably go with Seattle -4.5....it's a lot, but a score like 27-17 seems reasonable to me. I can see the Seahawks passing early against a defense that will probably be going nuts over Alexander, and then pound it on the ground later in the game to put it away.
I've seen some people liking Houston this week...but after seeing that horrendous showing last week against a lousy KC road team, I see no reason why they could win this game. With all the STL receivers back, Martin should do fine...280/1 is probably all they'll need from him, and let Jackson do the rest against the terrible Houston run defense. St. Louis -4 isn't a bad pick there.