Surprisingly responsive!
Actually has decent pressure sensitivity with a graphics tablet, as well as a shockingly robust level of customisation- the bg canvas can be changed to a custom preset, all the drawing tools present are adjustable. I actually ended up paying to upgrade it! Which, as an poor starving artist, should say a LOT as it might be the only art program I've ever paid for in an over 10 year professional career. My only wish is that there was a pc or even android version for on the go and sharing with my pc using wife.