Excellent! 

The superking mattress arrived rolled up and vacuum packed, delivered by two helpful and prompt delivery men.

It was not clear which way up the mattress should go until I took it out of the packaging, by which time it was too late to turn it the right way round before it expanded.  However, it is not that difficult or heavy for two people  to manoeuvre. Once the right way round, it filled out quite quickly.  And it is exceptionally comfortable.  We bought it for our spare bed, not wanting to spend a lot of money on it, but we’re tempted to sleep in the spare bed instead of our own.