Harry, whether you have the nuchal scan is very much personal choice. I was absolutely sure I wanted it and what I would do if I had a bad result.
I had the Harmony test as well, which the sonographer said was more accurate.
I had a low score for the nuchal scan 10 years ago, when it was a new test and went on to have the CVS test. All was fine but it was a rather horrific experience as I hadn't been expecting the result, hadn't appreciated that I could get a result like that and was completely unprepared. Add to that some lost CVS results, resulting in a retest and it was horrible.
I suppose it helped me with my thinking this time around. DH and I had already discussed it, 10 years ago and my feelings and our circumstances were much the same. I was much calmer about it and more prepared, which was a good thing given that, ay my age, statistically, the odds had moved on a bit.
Whenever anyone has ever asked me, I have (gently) reminded people that while scans are usually lovely and it's great to see baby, they are a medical test in a medical environment and an unexpected result is a possibility. I started off, this time, with a rather hardened heart, but softened as time went on and things looked more and more positive and saw baby bouncing around.