I had brought this product a few years ago (I think in 1997) and after using for a few months, discontinued its use!!
Yes, it was all that it promised in the ads (about being convenient, easy to use etc.) But, the ads did not mention ingrown hair. I liked it the first one or two times that I used it (though it IS quite painful on the arms, especially the upper arms). After the first few uses, I began to notice ingrown hair which could not be removed by the electric razor. You had to pull out the hair by first scraping off the thin layer of skin on the hair (using a pumice stone) and then using tongs to pull it off. It was a long process and a pain!! Hence, I finally stopped using it and started waxing again......
That’s my story, I dont know if others had similar experiences. I think I used to use it correctly, moving it in the opposite direction of the hair etc. so noone can say that ingrowth of hair was because of wrong use....
All in all, I guess you can use it for emergencies (as I do) when you dont have any time, but beware of ingrown hair!