Originally Posted by andrewwm

This isn't correct. PMUs and SWUs (and CR-1s) are both per-one way instruments. However, to earn PMUs, you have to reach 75k, and to earn your first batch of SWUs, you have to fly 100k (and then you'll receive another 2 for every 50k you fly for the rest of the year).

Since the op is not likely to reach either 75k or 100k, it's a bit academic as to how one would use them.

One benefit of UA that I forgot to mention is Economy Plus seating, which is quite nice and available after you become a Premier Member. However, the CRJ's (CR-200's really) don't feature any E+ seating, which is a fair amount of UA flights out of SYR.