Last year I travelled on the 932 IAD to FRA on a 777 the flight was full so there was no chance of any op u/gs or even SWUs.
We were comfortable in E+ A&B

I will be flying again in April to FRA from NYC (so via ORD is even a remote option)
Does anyone care to comment on the merits of the different flights IAD-FRA ?
916 5.15pm 747
952 6.40pm 767
932 9.45pm 777

Any particular days of the week to avoid- we're looking at a Tuesday departure?