I think Episode 5 is where MaM gets really good.. the first couple are quite slow, but as the episodes go by, you realise that they are quite important as a background to the whole saga... personally I don't know if the documentary is slightly bias in the way it presented some of what happened and perhaps a few things might of been left out - its hard to give an opinion to someone who hasn't watched it without risk of spoiling it slightly. Lets just say, some of the stuff the prosecution used as "evidence" and some of the stuff that was allowed to happen - you just couldn't make shit up like that lol.
I think I still preferred the OJ trial best though - apart from Travolta who I thought was pretty shit in it (I think his taut face just put me off everytime he was on screen) - I think I preferred it because it wasn't presented as a documentary and you could sit back and enjoy it without having to take a lot of information in - can't believe he got off.. disgusting really.