One goes one way, one goes the other :)
No reason to pick one over the other, any difference is swamped by the variability due to atmospheric conditions.
ETA: You've already missed the closing date for UTAG on the 881R anyway, so your only option is Paceline on the 881
I think I prefer the 881, on the basis it’s slightly downhill on the way back, so for an even effort you see your avg speed rising in the second half, other way round does go a bit downhill for the last mile but 5-9 are a bit of a drag and it’s tough seeing your avg speed drop!
One goes one way, one goes the other :)
No reason to pick one over the other, any difference is swamped by the variability due to atmospheric conditions.
ETA: You've already missed the closing date for UTAG on the 881R anyway, so your only option is Paceline on the 881