Ditto Tink, take your sea-sick meds daily as a precaution and look for a cabin on a lower deck mid-ship for your first cruise anyway (I'd suggest oceanview cabin). We've been on two Fantasy class cruises and the Glory twice. Both times the Glory was the rougher ride so I don't think you'll gain any ride advantage with the larger ship. The rule of thumb is, newer and larger ships operate on the longer routes (7-plus) day. Older ones get the 3-5 day itineraries. We cruise in the winter and we've decided we like the weather better on the western route and the itinerary better on the eastern. That's just our opinion. I think you'll be blown away whichever you decide.