Debian would be a Volvo Estate, its the boring practical family choice, the owner is soneone boring like an architect or a financial advisor.
Arch is a Vauxhall Nova, second hand battered owned almost exclusively by teenage lads who spend a lot of time/money modifying it (e.g. lowering so it can't go over speed bumps, adding a massive exhaust to sound good but destroys engine power).
Fedora is something slightly larger/more expensive like a Ford Focus/VW Golf/Vauxhall Astra owned by slightly older lads. The owners spend their time adding lighting kits and the largest sound systems money can buy.
Slackware is clearly a Subaru Impreza, at one point the best World Rally Car but hasn't been a contender for a while. Almost all are owned by rally fans who spend fantastic amounts of time tinkering with the car to get set it up an ultimate rally car. None of the owners race cars.
OpenSuse is a Nissan Cube, its insanely practical. It should be the modern boring family choice, but it manages to ve too quirky for your architect while not practical enough for van drivers.