Well it depends on what machine you are running, what kind of video you are playing etc etc etc.
I had a 5500, I bought tkcVideo from theKompany, it worked fine, just remember when playing videos you need to encode them right, if you take a video encoded for something else, it will probably play poorly. I used MPEG-1 at a rate of 1.5-2MB/per min and used tkcVideo for watching entire movies off a 512MB CF, only a few frames were visibly dropped in the movies, usually during action scenes with a lot of movement. Each Star Wars movie rolled out at about 120-130MB.
On my 860, it's worse though, I haven't tried tkcVideo on it because the tight fisted gits at theKompany said I'd have to buy all the products I'd just bought for the 5500 all over again. I'm stuck with the default players and Kino2/mplayer which feel much worse to me and I've not found a combo which comes close to what I had before with the 5500.
