Just tried Rollbit but my luck didn't let me get even 10x during 300 spins of Sweet Bonanza. Redeposited $40 and did bonus buys twice, busted all. Anyways, the site interface and game experience was good if I don't consider the dead spins due to bad luck 
P.S: Honestly, my bad luck has nothing to do with Rollbit since the actual RTP has been calculated over millions of spins. Game variance during my game session was an unlucky one.
The highest I got on Rollbit was 70x and 50x and it only happened once in the Big Bass Bonanza, but all the balance was empty because I only focused on getting the high multiplier and forgot to take a break for a moment.P.S: Honestly, my bad luck has nothing to do with Rollbit since the actual RTP has been calculated over millions of spins. Game variance during my game session was an unlucky one.