Differences between those ships are small. oosterdam is a few years older, but had renovations done last spring. It carries a little less passengers, which we like.
oosterdam doesnot have (yet?) the cabanas, neither the Tamarind restaurant and silk den.
If you like Eurodam, you am almost sure you will also like Oosterdam.
Are you taking your kids again? and how old are they. HAL generally does not attract as many kids as other lines, especially during the school season. If you are taking them at a time when mst kids are in school you won't find much in terms of other kids on board for them to play with. But they should still have the counselors - they may have them almost all to themselves, which can also be fun.
If it is summer, you will have more kids onboard.
Eurodam is an exceptional ship, but OOsterdam is also nice. My bet is that you will enjoy it, but see a few subtle ifferences that make Eurodam a bit better.
Exceptional is Good! (Eurodam cruisers 2/13-20/10)
This will be our 4th chartered-group cruise on HAL ships. We are surely looking forward to the ipod tour, the enhancements over MSS Zuiderdam and the MSS Westrerdam!
IMAGINE 2063 guys, no children (again) and a cruise tailored to the interests of our RSVP Vacations group. There is not even a waiting list, since this one has been sold out for months. --Rob+Roy, Langhorne, PA 8)