I love the fact that they have much more aftermarket support or upgradeable parts than most (production) handguns on the market.
those parts are readily available,
accessories are readily available,
I can strip it COMPLETELY bare in less than a minute,
less "working" parts than most handguns,
they are virtually indestructible,
they don't "rust" from CC,
they are EXTREMELY low maintenance,
you can get factory hi-cap (G18) mags for the 9mm and G21 mags for the G30,
they are accurate,
lack of "traditional" safety to fumble with in a hairy situation,
all my friends got them
oh yeah and liberals hate them !!!!
they always work,