Consensus on board is Hilton for hotels. I agree, because of range of hotels: Book at Hilton for business meeting, Hilton Garden for some trips, or even Hampton if you are pushing the budget. Plus the double dip is great.

But which airline to be your lead. From AUS, plenty of flights on CO through IAH or AA through DFW. MHO: Go with CO.
- Unlimited domestic upgrade opportunities on paid flights.
- Plenty of flights through IAH.
- With your milage, you should make Plat Elite, which has priorty for those free domestic upgrades and on reward seats. It has discounted capacity-free rewards and many bonus miles per flight. Also, can be used to get free domestic upgrade for the wife when she is with you.

However, if you are trying to work towards free international travel, AA would be better as it has more reward partners internationally.

Whichever airline you choose, try to stick with it to get top-tier Elite status.

Whichever you choose, be sure to set your Hilton profile so that you get that airline's miles when you double dip. Also, you should be sure that you get FF miles when you rent with Hertz. That needs to be set to your profile with them.

If you don't have a corporate card you must use, consider a Visa/MC that is affiliated with the airline you choose (Citibank for AA; Chase for CO; or Citibank USA for Hilton HHonors points) so you get even more miles/points.

Hope this helps.

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On the road, In the air,
I enjoy travel, From here to there.