Had a lovely experience with VS on an award ticket from East Coast US to LHR this week.

Was originally booked Premium Economy with family members. At check in, they asked if one of us would volunteer to fly economy (in a row of blocked seats, or extra legroom, depending on preference) in exchange for a free return ticket anywhere on the virgin network.

As I'd paid with minimal points I agreed and they said they'd let me know at the gate.

At the gate I was kept well informed and eventually they said they did need my seat, and reissued me a new one in a very quiet economy cabin with both Premium and Upper fully booked.

Upon boarding complete, the gate agent came to me and said someone in Upper had missed the flight so would I like to sit there instead, and I of course said yes, and lucked out with the Retreat Suite! Fantastic flight, great crew and staff all round.

I've actually noticed a trend of US flights lately with premium classes fully booked and economy incredibly quiet. It was the same with our BA flight out too.