When i got mine I ordered it with Ubuntu. I had a lot of problems playing video files and such, but Flash files weren't an issue. But I needed a Mac system so I converted it to Mac OS X and have had absolutely zero issues with videos except for, say, watching HD videos on YouTube.
EDIT: I haven't done anything as video intensive as, say, iMovie, but I don't even know how much of the system's resources iMovie uses in the process of making a movie so I don't know. I have the 2Ghz Atom and 1 gig of RAM. If I run into any memory issues I'll upgrade and see what happens. Other than that... I noticed that mini PCIe card on the front page but is it even possible to put that thing in the Mini 9 anywhere? To my knowledge the PCIe slots are occupied with a wireless card and SSD
, and nothing else allowed, but someone correct me if I'm wrong. I'm a n00b to the Mini 9 world.