A330/340 for me with the 2-4-2 configuration, couples chair by the window. A350 lovely aircraft as is the A380. B777 okay in 3-3-3 configuration but too tight in 3-4-3, check on SeatGuru before booking.

B787 okay for short haul in 3-3-3, certainly preferable to a narrow body, but too tight for long haul.

I would rather have 2x 7 hour legs in an A330 with a 3 hour connection in the middle where I can have a session in the gym and something to eat in the lounge than endure a 14 hour direct flight crammed in like sardines. For ultra long haul a night in the transit hotel in between two 10 hour sectors is essential and far cheaper than business class.

Choose you airline, aircraft type and flight timings carefully and you will feel the benefit on arrival.

Do you have sufficient experience of both to justify the comparison?

Mrs Uffers and I are travelling DXB - AKL (17 hours!) in business class in late December. It was originally a T7, but thankfully it has been changed to a 388.
We travelled with QR DOH - MEL in a T7 a couple of years ago, but that was in a 2-2-2 configuration so not too cramped. EK fly theirs in a 2-3-2 so it looks on videos very cramped and I must admit I wasn't looking forward to the trip.
We've flown in a QR 388 in business and
I like the idea of the bar area as you can walk around and chat to fellow travelers and bar staff. In a T7, the only option is to walk through economy, tripping over feet or banging heads or to loiter by the toilets, or the galley area were the FA's are having a break/meal. All not ideal on a long haul flight so an A-380 works for me.

My last trip to Europe with Emirates was A380 Sydney to Dubai and B777 to Venice.

The B777 was experience was terrible (only marginally better than the B747). Noisy, dry, cramped. The only savings grace was I managed to get a double seat at the back of the aircraft, with no one sitting next to me. I was lucky, all the other double seats were full.

The A380's there and back were superb, quiet, spacious, better atmosphere altogether.

I can confirm flying in a B777 is exactly like that, it is also "hot" inside them. Terrible experience.