We were on Eurodam in the last week of February (I'm still dreaming in Eurodam themes!), and had a verandah cabin, starbord, right at the forward elevators. We were on the fifth deck (Verandah Deck; doh
Movement? very little. One night during what the log describes "moderate seas" there was some movement, but it was always far, far less than anything I've ever experienced in a passenger train.
The floor to ceiling wall onto the verandah was lovely and seemed to dissipate any notion of dizziness (very minor anyway) that my wife experienced.