IMHO you already have the best "comfort" wheel/tire combination that you can get. Lowering your tire pressure on a 17" tire isn't going to make the ride much smoother and - like Papa in Austin said - it might cause premature tire wear and poor fuel mileage. I would go with what's on the door.

I might get some disagreement here but the TPMS isn't a lot of help when it comes to accurately monitoring tire pressure. I think it's there to warn you that you have a low tire. Get a good pressure gauge and go by that.