Our experts have checked the vn888 brand. It has a fairly simple registration, but only Vietnamese IPs are allowed. Checked deposits via Ezeewallet and Bank transfer - both allow very small sums in VND, but we have used 5000000. Deposited, tested the games and withdrew the remainder back. Took about an hour with Ezeewallet and around half a day via bank transfer. But the deposits and withdrawals are integrated with major Vietnamese domestic banks as well: Vietcombank, Techcombank, MB. Sacombank, ACB, Dong A Bank, Maritime Bank, Vietinbank, VPBank. These should work faster.
We have tested the games and found them fair, although there could be more choice regarding titles and providers. The games are tailored towards the tastes of Vietnamese players. Support is polite and helpful, especially in Vietnamese.