I was thinking of getting it, but i had read an awful lot of negative reviews about it.
Be sure to read the "money back" process. It's actually not all that easy. you have to supply a birth certificate and everything.
But the reason i didn't end up getting it is because it searches for the Y strain in the moms blood stream. So basically it's searching for the boy chromosome. It does not search for the girl chromosome bc mom already carries an X, so the blood wouldn't tell the difference. So basically it scans for the boy chromosome and if it finds it, they tell you it's a boy. If they dont find it, they tell it's a girl bc of deductive reasoning but not because they actually found an X chromosome (since they dont search for that since its in all female, mothers blood streams anyways). What i had read is that if you have had boys, theres a chance it could give a false boy result bc the maternal blood always has some fetal cells from previoius pregnancys floating around.
Since i have two boys already, i didn't feel it was worth the $$$. But maybe if this was my first and money wasn't an object i would consider it...but then again i read a ton of reviews and most of them seemed to be inaccurate.
There are now blood test offered from the medical community that can tell you the sex of your baby also. (think its called Materni21). TBH, i think nub theory has more a chance of being accurate than tell me pink or blue.