For stays <=3 days
1. If a pointstretcher is available, grab it. Best bang for the buck.
2. See if a good Priceline rate is available at a HH hotel that has a track record of honoring Elite status no matter what you pay.
3. If cent/point ratio is higher than 0.75c/point, got with the HH points redemption.
4. If there is no award availability with HH, encash your SPG points as the last resort. With a HH Diamond, capacity control is not an issue.
For stays >= 4 Days
1. HGVC points redemption.
P.S. I would rather stay at a Mid-level Hotel in an upgraded room with elite benefits than at a high-end hotel in the crappy section.