I almost always do 5 for 4 when redeeming points, and look for value in excess of $0.005 per point as compared to the paid rate. When traveling in Europe and needing a room for 4 people (vs two rooms) I will see if a modest copay upgrade can get me into the better room category vs the base room available for an award. Next month I am at the Hilton Metropole for 5 nights, on an award stay for 240k points. I called and got an upgrade to a 2 queen room for 100 quid per night. That room was going for £400 per night as a paid rate. The savings/avoidance of £300 per night x 5 nights x 1.30 FX is ~$2,000= over $0.008 per point. I am chuffed . And absent points I would have paid either the £400 or probably more for 2 rooms.

I am down to 1.5 mm points. lots of good usage lately including 2 rooms at the Paris Opera in March (no rooms for 4.). I wouldn't want to be under 1 mm as sometimes travel opportunities develop quickly.