I respect that you may not like this technology. I think you are perhaps overestimating how hard it is to quantitatively or qualitatively judge what customers think of it.

Qualitatively: ask your waitstaff if they keep getting called over by customers saying "I pressed the devil box and it didn't work! I hate this!"

Quantitatively: you get credit card numbers and email addresses. See who comes back. (Bonus points: if they don't come back, ask them why not.)