Sailed on NCL out of Houston about 5 years ago, the port is in the middle of nothing and quite a ways from either airport, but still a great cruise for those in the middle part of our country. Many from NM, TX, OK and LA drove to the ship. Others did fly in. The cruisers were a little different than some who sail out of Miami and Ft Lauderdale. Mostly we had a great time.
We're booked on back to back cruises on the Sea Dec. 6 & 13 out of Houston. Really looking forward to it. Haven't decided how we're getting there yet - we live in Vancouver Canada. We will be keeping our eyes open for cheap flights from Seattle maybe.