I used my 312B on my GF in several ways. When she is a good girl I can use it to take her to the edge of orgasm and hold her there for as long as I wish. When she has an orgasm from this she is just out of mind crazy multi orgasmic. She describes it as mind blowing full body orgasm whatever that means. When she is not so good I can bring her to the edge, keep her there, and then deny the orgasm. It also has a "torment" mode which is a great punishment.
That being said, it is very pleasurable to use on yourself also. I can bring myself to the point where pre-cum is oozing out and dripping down the shaft like a burning candle sometimes. It always ends in an orgasm for me.
I have had mine for about six years now and it still runs strong. At 700 plus 300 or so in accessories and it still works out to under $1.00 per orgasm.