I've used sportsbook.ag for many years and while their payouts have always been a bit slow, they've been reliable. I've always been able to cash their checks and have suggested them to many friends.
However, the only way to withdraw funds now is through Bitcoin...even when you haven't used bitcoin to deposit. They still list check and wire transfer as payment methods, but can't say if they will ever be available again.
Warning - if you don't use bitcoin, make sure you don't use sportsbook.ag. Even if you use bitcoin, I would now be cautious of their changing policies and I wouldn't trust them.