Pretty good, must be a lot of use to some users.
I'm personally not into sprite animations, but I can understand how useful this must be.
However, I must admit feeling a little disappointed after watching. You see, the word 'advanced' in the title got me excited because for a moment I though it was going to be a tutorial in how to construct *your own* sprites.
It would be really nice to see that particular tutorial here on Newgrounds...
TDM