Me personally, I dont think its necessary to use one for exercising the pelvic floor muscles when you can get adequate effectiveness just counting the reps & sets yourself.
This device wont make the exercises more effective, just counts them for you, so could be helpful for those with memory problems, for sure.
Quite a steep price for what it is. Pretty sure, if more were interested, that MoS could make one much cheaper.
Really though, doing a kegel routine like found in the following threads works the muscles so well, that you can save the money to buy other things.
Only purchase one of these, if you have problems remembering the amount of sets & reps your doing.