I had a Groupon, and am very happy with the results. The procedure was painless, and there was visible positive whitening of my teeth. At the price I paid it was well worth the 50 minute procedure
The owner was very accommodating seeing as I'd called to redeem right near the end of the Groupon window, and also considering I had jotted down the wrong time for the appointment. Very professional, and he explains the whats and the whys as he proceeds (Mostly you're just sitting with the light device shining on your teeth, so bring headphones)