We were on the Spirit for the Norway/Iceland/Ireland itinerary in late Sept/early Oct. 2019. Due to Hurricane Lorenzo moving up from the Gulf, there were several changes in our itinerary. It resulted in some people on the ship getting bent out of shape, and vocal demonstrations. When you stepped back to look at it, most of the changes were reasonable due to weather, but Norwegian could have handled them better.
Transfers from airport and embarkation were pretty smooth and as we were the only ship in port lines were short. We filled out the medical report but were never asked for it and never asked if we had any symptoms.
As for the ship itself, I was pleasantly surprised. Due to the age of the ship I thought it would be more run down with limited facilities but I found little of that. There was a good variety of dining, and we tried nearly every dining venue on the ship. Our favorite was the Teppanyaki grill. We ate there twice, once lunch on the last sea day of cruise when the two of us were the only ones there but we got the same show and a LARGE quantity of food. I can think of only two or three dishes that were "meh" and none that were "send it back" quality. Most of the food was impressive, especially the soups which I thoroughly enjoyed. The "meh" dishes were my steak at Cagney's grill. It was a thin cut, cooked medium instead of medium rare, and not well marbled. I had a breaded fish in the main dining room that was doughy. Some cruisers were tweeting about "stale food" on the cruise but I could not think of anything that fit that bill, except for dry hamburger buns. (see Twitter handle nclhell1. Please note I disagree with this person on most points).
As for our cabin itself, it was not quite up to the quality of other cruises but was sufficient. The main issues were it having only a single power outlet, requiring extension cords to power our CPAP machines, and a tiny toilet room that required care when sitting and standing. The TV was terrible, few useful channels and a tiny screen. The mini-bar fridge was overstuffed so opening it took care. The bed was extra firm which suited us but might bother others. The balcony was small, and we did not use it much due to the rough, cold weather. Our steward never left us ice, and failed to replace our cleaning list/bag after first use. Walls were thin, and we could hear conversations of our neighbors, who were thankfully pretty quiet, except for some coughing fits.