In Premex's example, part of the boss' message is that exhorbitant luxury spending is a deliberate marketing tactic. So trying to save them money doesn't do them any favors.

Outside the US, I'd just take the best hotel and not worry about the points.

Inside the US, I'd make a list of the top three properties in each of the top 30 US cities, and prioritze them by chain:
1. Four Seasons or Ritz Carlton
2. Starwood
3. Best Independent
4. Other chains

For the non top 30 cities (where I usually go for work), I'd pick whatever chain suits my point needs from the best two properties.