Under the 6" mark, I would look to the T-40 or T-9 and or the TP series if you like polymer,
The MK is a real pocket rocket , my last partner had one for a BUG and always called it his little Pokémon,, supposed to mean pocket monster in Japanese,
I carry both the T-9mm and the Pm9, the T has run full tilt boogie from the box, now with just shy of 4200 rounds down range, the Pm9 has been a hit or miss, it was recalled due to the barrel ramp issue , and the trigger guard pin walking,, took 800 rounds to make it feed from slide lock,, more than likely the ramp issue,,
Since return for warranty work it has run fine and now is approaching another 1k rounds with out a hick up.
Placed some "sand paper" grip tape on it and changed that sights out to the "Big Dot" and it rides every where in the pocket now