Until April 26 I had never flown east from the US to Ireland on a daytime flight, but since then I've flown on D8 1843 to Dublin twice. It's something of an odd experience after 30+ years of flying through the night, but it suits me.
Until April 26 I had probably made a few hundred flights from the east coast of America to Ireland (or Britain on occasion with a connection to Dublin). Each of those flights followed a familiar pattern: get to the airport in the afternoon/evening, check in, board, take off and 6 or so hours and one dinner later I was in Dublin (or London or Glasgow or Manchester or Bristol, etc.). And it was morning.
Daylight and exhaustion greeted me each time. Not with D8 1843, however. I got to Dublin somewhat tired – and bored (no TV on Norwegian) – but by 1:00am I was in my bed. Sleep didn't come easily after the trip but it did come and when I woke the next morning the exhaustion I usually experience on my first day in Ireland wasn't there. There's a lot to be said for that.
However, if you don't have your own bed waiting for you it may not be the ideal way to travel. If you need a hotel you'll end up paying for a night's sleep before you see anything of Ireland. So, Norwegian's daytime flight may not suit tourists coming to Ireland but for those who live in Ireland I think it's great.