To add balance to the negative reviews, I've had a mostly postitive experience at Betti. There is a good selection of games, they allow feature buys for UK players (this is rare), and the withdrawals, if on the slow side, do get processed.

My only criticism is allowing players to cancel withdrawals (probably explains the bad reviews, people get impatient and tempted to play more and cancel their withdrawal thus losing their winnings) and limiting it to 2000 EUR at time - but this comes with the territory of playing at a Curacao casino. Another downside is some of the games seem to be the lower RTP variants.