I hear they limit fast but I don't know for sure. I wouldn't leave to much money there until I see an official rating from SBR but so far it looks good: low juice and high limits for relative small players (thousands on US sports).
They limited me to 1e on everything but still payed my account balance ≈8kE without problems, so I guess they are pretty safe.Also they dont offer any bonuses so there isnt any big reason for confiscation.
First 5-7 bets everything works nice, instant withdraws, high limits K+. After hard hammering those lines, limit gets down to 10% of initial limit, few more bets and then you're in 1$ range (10-15$ on big events) even on multiples. So regardless if you are winning or loosing, if you are backing their generous lines they will limit you hard and answer for this will be: "you have no personal limits, this is our trading team comercial decision". Then the withdraws stop beeing instant, bet setlement is starting to take up to 4-6 hours when official result is out. So they will let you know when your action there is not welcome anymore. And this will happen very quickly if you're not backing 13 combo multiples.