Margo & Betty - We also found that particular Vietnam cruise on Silver Cloud about two weeks ago and made a reservation. Even with the airfare (we were still able to get upgradeable coach seats on UAL), it saved us a fair bit of ka-ching vs. Radisson's all-in pricing on the South Pacific/SE Asia world cruise segments.
One of my very good friends has transferred to Singapore, so we're going a day early to celebrate Christmas with her. That's an added perk for us.
Betty, if you can't make it, let us know if there's anything we can look out for or bring back for you from Nha Trang. Even better, if you hit the lottery or can otherwise make time, come join us!
I'm looking forward to talking with Olivia on VJ7 about her SS cruise as the itinerary is so similar to this one. Cheers, Anne