craz & dlen111s,

Some good points!

Bird in the Hand -
1) 9:25 seating - I am seated 16C on the 752 (which I wouldn't want to lose if any delays occurred).
2) Even if I EUA on the 8:30am - MHT-EWR is only 70% on-time - which means a late arrival and I'm back to 9:25am with no confirmed seating or flight class (possibly causing me to miss this flight)
3) Doing the run and check at the gate in EWR would allow me to weigh the option of 9:25am confirmed seating vs battlefield upgrade on the spot (if any is left to be had).