Looking at the following flights all on the same day:
SW 64000 (would pull from UR) on 737-7
Delta 80,000 (would pull from amex plat) coach -would have to pay $150 for luggage round trip ERJ 175
Avios 132000 (sitting in the avios account) in biz class to get free bags on ERJ 175
avios 66000 (sitting in avios account) in coach would have to pay $150 for luggage round trip on ERJ 175
I could use amex travel credit for the baggage fee. Or I could save it for another flight.
Flight is 2.5 hours.
Flight is with 2 young children.