As far as I play, I have never experienced any problems. Indeed Sportsbet.io has had problems with users but I personally have never been affected by the problem. I'm sure Sportsbet.io is still safe, but if you are not sure or doubtful. Then leave it.
IMO,sport bet having more games than other sportbooks so people have this as only option for few games.
There are other sites that has a lot of games and odds in their platform, why people like sportsbet is because they have a good UI and it loads fast.
Personally, this is one of my choice and when it comes to safety, we can evaluate that for ourselves because their main account here has red trust but it doesn't mean they are scammers.
https://bitcointalk.org/index.php?action=trust;u=832366
Well, on the other hand sportsbet.io continues to make progress even now this site is known throughout the world since becoming a major sponsor at Watford
I'm sure they also maintain a reputation in the betting market