Do raised (double-high) air mattresses hold air better than low-profile ones?

Height and air retention are separate issues. An 18-to-22-inch raised bed is easier to get in and out of, but durability and leak resistance depend on seam construction and beam design. Across reviewers, the most common complaint in this category regardless of height is gradual air loss overnight, so look for models with the largest body of reviews specifically praising overnight firmness.