Well, this is not the only positive feedback you are seeing. there are a complete thread in service section about reviews of cryptomixer.io testers. lots of people used cryptomixer.io and give positive feedback there. and the onwer was gave a big giveaway to test the service. everyone got 0.01btc free to test and review cryptomixer.io.
I don't remember that thread link now . hope someone else could mantion the link here.
I was also one of the beta tester for cryptomixer where i have got 0.01btc for free and the mixing really works as i get payment from 3 diffrent address with reasonably low fee in that mixing.