Flash seems to work well.

There's an option in the browser to turn plugins on or off or on-demand, which works basically like FlashBlock, except that once you click on a Flash applet, it turns them all on for that page, not just the one you clicked. I don't know what would happen if there were other plugins for a page: whether it would just activate the one plugin needed to run the applet you clicked on, or if it would turn them all on.

I played around with it for a bit, and everything seems to function properly, even though there are occasional UI issues due to the creators of the applets not providing for a touchscreen UI. Videos, games, and animations all seem to work fine.

Battery usage doesn't seem outrageous at all. I didn't play with it long enough to see how quickly it would drain the battery, but I did note that it didn't get even remotely as hot as I have seen it get with other applications, and I never saw any performance issues. It seems like they've actually done a decent job of optimizing the code.

The install is huge, though: over 12MB, and it's not flagged as SDCard-installable. As such, I've deleted it for now, because I have way too many apps installed, and I was already getting quite low on space.