Out of IAH, you also have a pretty decent option with AA. There are 7 (I think) nonstops daily to DFW and from there you can connect to just about anywhere. If you're willing to almost always add that extra segment on, then you can benefit from the hub-access without the hub fares (necessarily). Plus, you'll add an extra 1000 miles to every flight (500 min EQM/EQP each way) and 2 segments, which could certainly add to your status.