All of the European and US experiences are more similar than they are different. Virgin has a few extra touches; I recently tried SAS business from ATL and their meal service was very nice. All of the actual beds are similar: kind of narrow, awkward bumps and gaps, but yes they are actually flat.

I love the 763 because you actually can sit with your travel partner. I dislike the high partitions and doors on newer planes. They make me feel a bit lonely.

Using lie flat products is of course very wasteful of energy and, for east coast TATL and transcontinental flying, a mediocre opportunity to get any sleep. The Premium Economy products are much more sensible. Fly to Europe on Saturday, walk around town on Sunday, spend $200 extra to get real sleep in a top line hotel. Be ready for Monday and save $3000+ on air fare. It works.