Let's explore the opposite direction, just for the kicks. Assuming unlimited funds, and, just for a second, suspending any potential concerns about the negative impact on gear familiarity as a result of changing gear too often, what in your opinion would be the optimal composition of the diver's toolbox, specifically? Separate cold- and warm-water sidemount kits, multiple sets of back-mounted manifolded doubles with wings of varying sizes, a singles setup, a rebreather? More than one rebreather? Independent doubles? Jacket BCD? What would provide incremental benefits, however small, and what would be 100% superfluous?