I don't have this but a good friend of mine swears by it! She got KU her first cycle trying and says it was the monitor that did it. She had a really unusual ovulation though so, I don't know if it'd be as worth it if you're pretty normal and can see from charting and opk's when you ovulate already.
Actually, if you are regular, then it's worth it because you will use less of the expensive test sticks. If your cycles are long, it can get expensive. Keep in mind that you can gear up to ovulate and not ovulate; the monitor will go on autopilot after your first LH surge and you can miss ovulation. How about trying OPKs, OP? The Wondfos on Amazon are really cheap.