I tried Loot.bet once but Sportsbet.io is a new one to me. Loot.bet is often advertised in some Esports betting sites that doesn't accept crypto so I got curious and checked it out and overall experience I would say is pretty good.
Loot.bet is just like other fiat based sites but sportsbet.io and other crypto-sportsbooks actually have the same odds provider from what I have observed and the odds changes and markets are the same for all of them.
If sportbet.io covers the matches you are looking to bet on, then you should settle with them because they are one of the best sportsbooks we have here in the bitcoin community. There are others as well which allow betting on sports with bitcoin, but sportsbet.io are still ahead by significant margin.
I did check Sportsbet.io and from my experience I can say that it is a pretty good website, pretty easy and hassle free in my transactions, might be because it is small amounts but overall experience with Sportsbet.io is good, I would recommend it because they don't just cover Esports, they have other sports too.