I generally travel between DC and NYC, and I'm nearing 20,000 reward points. I'm interested in how people on this board would use the points. I realize this is a personal decision, dependent on what value an individual places on first-class service, etc. But forget about what makes sense for me ... what would you do?

The DC-NYC options include:

6 one-way rides in coach (18,000 points)
3 one-way rides in business class (19,500)
2 one-way rides on Metroliner/Acela Express (16,000)
(Nearly) 2 one-way rides in Acela Express first class (21,000)
10 one-class upgrades as space permits (20,000)

Another option, I realize, is to split the hypothetical 20,000 points into multiple rewards -- say, 3 one-way rides in coach (9000) plus 5 one-class upgrades (10,000).

I'm sure your ideas will help me, so thanks!