Overall, as a bookmaker for betting it's not bad, but there are a couple of things that didn't sit well with me.
The first thing that stressed me out was the betting limits. I had a moment when I wanted to bet more on an event that I thought was sure to win. But then the system says to me: "Stop, guy, you want too much". I realize that every bookmaker has its own rules, but it's still a shame to be restricted at such a moment.
The second thing is the design of the site. Maybe it's a small thing, but still. Their interface is so... Well, how can I put it mildly? It's not very user-friendly. Yes, the functionality seems to be all in place, but sometimes you have to look for where what is located. It's a bit confusing, especially when you're new to the platform.
But what is definitely good about 1win is the bonuses. They give pretty good deposit bonuses, which is nice. And the selection of events for betting also pleased, a lot of interesting things can be found.
So if you are ready to put up with some limits and not the most convenient interface, then in general 1win is quite a decent option for betting on sports.