I have tested this mixer and here is my opinion about it:

-first of all the process is super easy, the website is not something complicated and everyone can understand how things work
-I have tested the service with 0h delay and it worked perfectly, immediately after my transaction got 1 confirmation the mixing was completed
-the fees are very low and I like that you can modify the TX fee is you need your transaction to be confirmed faster.

I have noticed a problem with the TX fee. When I completed the mix I put 0.00008btc as the fees for my transaction but when I received the transaction it was only 0.00002btc. That wasnt a big problem since he transaction confirmed in a few minutes but I think something is anyway wrong.