Having first hand tried my hands on tweaking the phone to the most maximum stable speed possible, I'd say there's credit to what CreativeTone said, and it's not just a "placebo effect." Pen stroke lags can be observed at lower clock speeds compared to when you overclock it. Also, I notice the tendency for MyPaint to crash on attempts to run it while overclocked at the least stable speeds (mine starts from past 950MHz and outright reboots when I set it to 1.15GHz), so I played along with overclocking and tried starting MyPaint from the terminal to see the error messages it prints upon crashing. Well, my limit is 950MHz so yeah...