I prefer to get through passport control quickly, then I can grab a water & wait for the bag sat down on a seat. Although, if the wait is 15 minutes, I can cope.

As for business class, well I don't know how long you take from the US, but since it's ~24.5 hours round trip from London, lets estimate 36 hours in the air from the US (both ways). So $1000 economy to $5000 business is about +$110 per hour in the air ? A big difference.

I suppose for anyone worth a few million it's business class all the way, but some of us haven't made that much just yet. For your typical " middle class" economy, or premium economy is where it's at.