In 5.16 PPSSPP is not stable. The gameplay is not smooth. The audio skips. Controls are not precise.
In Lumines and Lumines 2 there is a line that sweeps left to right across the screen, clearing blocks that have been matched up. This line disappears for long periods. The audio drops out at the same time. I don't know if PPSSPP is multi-threaded, but it feels like a background process freezes for 10-15 seconds at a time. The audio skips and crackles as well. Its like the audio and the sweeping line are controlled by the same thread and it is starved for CPU time.
In Loco Roco 2 my PS3 DS3 wireless controller is non-functional (except for the circle button to zoom) - I suspect it is looking for the accelerometer controls that I have disabled in qtsixa. The directional keys worked in 5.15. They do not work in 5.16. Re-mapping RightAn.Up, Down, Left, Right from accelerometers to the right stick in settings did not help.
It may to be related to the default mapping of the controls in 5.16. Games ran much smoother in 5.15, but maybe 5.15 was just slower so there was less stuttering/freezing.