Just fyi, I made a quick mplayer test to get an impression of the current speed.
I ran the mplayer part of this test here:
http://www.amiga-news.de/en/news/AN-...-00011-EN.html
I used the mplayer port from os4depot.net, not the MUI version as it claims to depend on 4.1.
It ran for 977 seconds, so roughly 1/6 of the speed of an G4@1GHz.
Of course, AltiVec might give quiet a boost to the performance.