For those who frequent the Caribbean, would you choose JetBlue (Even More Space seats) or Delta (First class) for a five hour flight to Aruba from the Northeastern USA?
Our home airport is BOS if that makes a difference.

My spouse is a reluctant traveler, but his extended family has booked a spring trip to Aruba and his father (my F-i-L) would like join the group. DH won't be comfortable if his dad travels without him, so I want to make the trip as stress free as possible for them both. (We lost my M-i-L a little over a year ago and they are a very close-knit clan. Happily, DH will enjoy the beach once he actually arrives in the Caribbean, though he'll despise the process of getting there.)

I'm the eager traveler who does all of our research and bookings. While we aren't price-insensitive, we do travel in J more often than not these days, but I usually book off peak times or far in advance, neither of which is possible here.

JetBlue is cheaper and has several flights per day, whereas Delta just has the one nonstop, but the up-charge between B6/coach and Delta/first is less than $100 for the flight time we prefer.

I could choose non-stop flights for them on JetBlue (A320 or 321) or Delta F (737-900ER.) SeatGuru suggests seat specs of 37-39/17.8 in Blue Extra/Even More Space for the former, 37/21 on the latter.

As far as mileage earnings go, B6 is the winner since we pool points. Otherwise, I have no strong reason to select one over the other. There's no lounge access for a Caribbean flight, and checked luggage isn't a factor. Since I'm an Alaska MVP, I really only experience BOS terminal B and occasionally E these days, having no idea if A or C is less hectic in 2023.

Can anyone add any useful facts or opinions to help me decide which airline to put them on?