I have the Mistress that doesn't have the vibrating bullet to put inside, so I really don't know how the vibrations are in that one. I will say, though, that as a stand alone dildo I absolutely love the Mistress. It hits the right spots and is phenomenal.
We haven't tried the vibrating variety, but we do have both of the dildos listed above. They are both very good. I would recommend the Mistress for the beginner.
We enjoy Vibrating Mistress, Vibrating Leo and also Vibrating Leisure. The Vibrating Leo is a little large for me, but the Vibrating Mistress and the Vibrating Leisure are great. The Vibrating Leisure is a little longer than the vibrating Mistress(7 inches vs. 6 inches). My wife loves to masturbate with the Vibrating Mistress and I love to watch her cum.