The Airbus vs. Boeing debate goes on and on. Here, it's about the newer Airbus 350 versus the Boeing 787 Dreamliner. Realistically, the A-350 could only compare to a B-787-10, the longest version of the Dreamliner. That said, they often pit the A-350, which could carry a lot of passengers in 2 class configuration, against the B-777.
I have flown on 3 Boeing 787s in the last 5 years. Two were medium-haul and one was transatlantic - Rome to Philadelphia's AA hub.
I just flew on the Airbus 350 for the first time about a week ago. It was by Finnair, picked up at Helsinki after transferring there for the flight to the U.S.
I was truly expecting more from the Airbus 350. It does what it's supposed to do. It seems to be getting more sales than the Boeing.
I prefer the Boeing 787 Dreamliner by a slight margin. The most important thing is that the humidification felt better in the 787. They say the A-350 is quieter, but it's negligible to the untrained ear. Even though some complain that the crew can lock and control the window dimming on the 787, they did not do this on my flights and I loved it, complete with the big taller windows.
The A-350 metrics seem to benefit the operator. The A-350 can seat more people, it burns slightly less fuel, and can fly slightly more nautical miles, but it seemed crammed and I didn't like the feel of the cabin, right down to shades on the windows. In waiting on the delayed plane A-350 for an hour, the heat gain against my window - with the shade down - was too much. I got up and walked around the rear galley where the air conditioning better cooled me down.
Both have 3-3-3 seating and they say that the A-350 cabin width puts a few more inches on the seat. That doesn't come into play for me. Not only that, Airbus puts in more thin Recaro-looking seats that seem hard whereas the Boeing puts in seats with a more conventional sculpted silhouette.
It's subjective. I didn't find the A350 all that much quieter and like the "open sky" architecture of the 787 cabin, the seats, the dimming, and the humidification.
The A-350 has a straighter looking wing angle with curled wingtips that look cool when they are maneuvering. However, the fully upward curved wing of the B-787 is stunning. The B-787 is a slightly better looking plane.
I wish more carriers of 9 abreast aircraft would follow Japan Air Lines' move (in their B-787) to 2-4-2, which would make the Dreamliner more of a dream.
If 9 across (3-3-3), I would go with the Boeing 787. However, I could skip this debate and step down in size to Airbus's latest A330-900 neo. It's got some up the upgrades, and keeps skinny harder seats; however, the 2-4-2 seating is the way to go for more comfort.