xp difference between single player/handheld and two player/docked modes

because of my workload this week i havent been able to grind as much as i want, but

here's my question for you beautiful xp grinders! particularly cerulean cave chansey combo-ers:

between

1. handheld mode guaranteeing easy great/excellent throws, and
2. docked mode using a support trainer for that second ball and sweet synchronized bonus,

has anyone who has experience with both modes noticed a difference in consistent xp results over longterm grinding?