Facilities are basic. Consider buying C-class on VN (fare difference is not huge) and you will be able to use Domestic Business Lounge (actually it is an airport lounge, but it is VN branded): plenty of good Asian food, full bar, lots of nice seats. Otherwise facilities are veryyyy basic and air-con is malfunctioning.
PS. VN Domestic Business Class is very good: full hot meals (2 to choose from), full bar, nice F/A's.