I have been on their boat before. You will get a stamp in and out of the country IF you have a multiple entry visa. Since they won’t be able to issue visas on the boat.
It is not nearly as nice as Sta Cruises, but they are cheaper. It is an older boat, and most of the crew is from Mainland China , Vietnam, etc.
If you do go, take a note book and some DVDs to enterain yourself.