Based on the announcement on Roobet's twitter, it's only been a few days, exact date August 7, but the loading in the sports betting section is a bit slow, it seems they are still improving things that are lacking in their sports betting display.
It was on the 6th of August 
Source
But all in all you are right, the loading times could be a bit better, and the UI could be designed a bit better here and there. All in all, it's very easy to use and I'm sure Roobet will invest more time and money to improve the sports betting feature.