That was me, and I ran it and I commented that it was usable, but it didn't run well.

Well, I guess I just have higher standards than you. I like to be able to see all of my menus, for one thing. I commented that the IT's screen size cuts off the bottom of the menus, and if it does that, it isn't running well. I had a taller virtual screen when I tested it, and I was actually curious if Gimp would resize its menus if the screen was too small; your screen shot answers that question with a sad little, "no."

As to performance, I was running two window managers (Hildon and XFCE4 via VNC) simultaneously, so my performance may have suffered. I found browsing a directory of pictures to be pretty unbearable, GIMP took 4-7 seconds to create a thumbnail for each of the 640x480 images. And image manipulation wasn't much better; a simple color balance took 30 seconds.

In short, I don't see much point in running GIMP on the tablets. The interface is completely unsuited and the processor is underpowered.

EDIT: On a related note, can anyone fix MyPaint so it has no "dead spots" on my screen? That one feels like a killer Tablet app to me, if only it worked on my tablet.