I think that NIPT is the same as a Harmony test (according to an ARC leaflet I just read), so if you look down this board, you will find loads of posts on it under the Harmony name.
It's meant to be good because you it's very accurate and can be done as early as 10 weeks, non-invasive as just some bloods taken and sent to the US.
I had one in February at 11 weeks but I was in the unlucky minority with not enough fetal DNA in my sample so I had to go back at 13 weeks and then wait again for the results, and in my case they were bad - baby had a chromosomal abnormality and we ended up terminating.
The test seems very good though and I'd recommend it, although it was very expensive - cost us around £700 IIRC.
HTH - if you have any questions I might be able to help with, give me a shout!