Very practical. Just know your ammo. If you're worried about over penetration use 135 gr. bullets. Double tap also makes a round that fires a 135 gr hollowpoint over a 90 gr. ball.
Not often as ammo is high.
Whatever is cheapest for practice. Double tap for home defence/carry. Dont reload...yet.
It's as much power as you can reasonably get into an automatic pistol [aside from .40 super] So I chose it for home defence as well as concealed carry.
Best gun Glock makes imo.