I have been provided 0.05 ETH from owner to test the service (although 0.1 ETH is minimum for mixing  ).

As per my my experience with site, I can say site is quite professional and legit. It does what promised.
In first step we are required to give receiving address and have to choose a dynamic service fee ranging between 0.8 - 3%. Site claims higher the fees, higher the privacy though I would like to know more how more fees ensure more privacy.
In step two site generates address to which ETH needed to send along with hash signed message. Thus, everything seems green flagged in step 2 too.
Step 3 is nothing but the confirmation message that mixing has been done.
It takes nothing more than 5 minutes in whole process. I sent 0.1 ETH to generated address and got 0.099 ETH (0.001 service fee) on receiving address all within 5 minutes from some random address. Thus I could say whole site is automated and genuine, there is nothing which seems like possible scam.
Suggession- I would like to see if site can break deposited amount and send them to multiple addresses in future.