After first use I was blown away - if you'll excuse the pun. I'd never used a toy, let alone a vibrating toy, and was very pleased with the sensation...
I agree with the prior comment saying it needs to be another inch (or so) deeper in order to allow for a true deep throat experience...
Also, after a few uses the internal rubber began separating from the "mouth", and I had to attempt a repair with liquid cement... and even that needs to be redone now that some time has passed. (Probably a symptom of needing that additional inch or two!)