I use AGR for WAS-NYP and return trips quite often, and almost always in coach.

If I were to buy the tickets, each one-way in coach is $70-$90; a business seat is $35 or so above that. You're paying more than double the points for what would be 50% more in dollars for somewhat more spacious accommodations and a can of soda.

The accommodations shouldn't be understated too much-- not so much for the seat itself, but the fact that the business car will be less hectic, and it will be easier to find a seat during crowded times. I have been on trains where people are standing all the way from NCL to PHL. But on the other hand, that's really only happened on Friday evenings of holiday weekends; otherwise, finding a coach seat hasn't been a problem, especially if boarding at WAS or NYP (as opposed, say, to MET or WIL) and especially if you are quick (at NYP) or can get in line (at WAS) at least a half hour beforehand.

I have taken Acela Business for work, but only about twice for personal trips, when the schedule demanded it. It's nicer than the Regional, sure, but I do not value bigger windows and a half-hour shorter trip (often less, due to delays) at almost three times the points or twice the dollars of a coach trip. It's equally crowded as the Regional.

If you're seeking maximum value, IMHO it is clearly the Regional in coach, because of the premium redemption levels beyond it versus paying for the upgraded accommodations. One of these days, of course, my interest will finally outweigh the opportunity cost and I'll splurge on Acela in First, with zero expectations other than sated curiosity.