Does the LuxeErgo 3400 come with a trial and warranty, and is it made in the UK?

Yes to all three. Luxe Mattresses are hand-made in the UK, and the LuxeErgo comes with a 100-night home trial and a 10-year warranty. The trial means you can return it for a refund if it does not suit you, provided it is undamaged and unstained, so use a protector from the first night. The warranty covers manufacturing faults such as sagging beyond the maker's stated limit; it does not cover normal softening over the years or damage from an unsuitable base.