For about a minute after I start up BlackInk it's fine, but after that the more I draw, the laggier it gets to the point where I just give up. This happens whether I use my mouse or my Tablet (which is a Wacom, but that's irrelevant, I think).
I know it's not my computer, as my specs are:
AMD Phenom II X6 1090T @ 4.0GHz
Crossfire AMD HD 6770 and 5770
8GB DDR3 1600 RAM
It's the only thing that's keeping me from upping from the trial to the full version. Program itself is incredible.