They're very snappy for me, even on a zillion year old MacBook... Never seen them slow. Have they always been this way??? There's got to be something wrong with a driver somewhere. Have you tried trashing your prefs?
Yeah, it's always been this way. Multiple machines over time, many versions of After Effects. AND I've experienced this on Mac Pro towers too, not just my Windows laptops. I think I just finally snapped tonight, doing a lot of roto under the gun and screaming for the shapes to be the way I want them to be.
Your video smacks of the same performance I get in Photoshop and Illustrator, even on large canvases (Photoshop) or with high rez placed images that I'm tracing (Illustrator).
I'll do the toss-the-prefs but again, this has been a thorn in my side for a long, long time.
Try making sure that you've disabled the OpenGL enhancements for drawing panels as well as for Previews and Renders (it's called hardware acceleration for panels, or something to that effect). Do you have any third party input devices enabled (wacom, intellipoint, etc...)? Their drivers may be problematic if not updated.