I just found a way to randomize parts on the ESX

Hidden under the move data function (shift+move data) you can select Move, Repeat or RANDOM.
What I like to do is set the pattern length to 8 and:
Hit the part i want to randomize
Hit [shift]+[step2/move data]
Turn the big dial so the display says "MoveData Random"
Hit [shift]+[step2/move data] - the part key and [step2/move data] should blink
Hit [shift]+[step2/move data]
Done! Now you can just hit play and listen what parts you like and so on.
I guess alot of people know this allready, but im sure there are lots of people out there who dont read manuals like me.