Having about a week's worth of banked Hilton points and Hyatt points has saved us thousands of dollars several times traveling last minute and especially overseas and during peak holiday times.

Have never had an issue redeeming, even when our account hasn't quite reached the right level of points (Hyatt) they hold the room, knowing we'd accummulate them by the date of stay. This is in contrast to * wood that will only hold a points "pending" reservation for 7 days, not trusting loyal customers to make good on the points, even with months and months of lead time.