I've had success introducing Kitsu to my colleagues (artists). We had to put time and afford to get to understand it but in production it helped us. However I have to admin that the UI is not straightforward and it is not a pleasant experience. Our team leader straight up refuses to use Kitsu because of the interface and he said he cannot imagine using it for client review because he would have to spend time teaching the client how to use it.
And this experience was similar with everyone in our team trying to use it for the first time they were confused and I had to explain a lot. The review experience is lacking compared to something like frame.io