Hello Rikkie,
I just had a quick view on the OMB site, which looks interesting.
f.i. the style playing using external synth's soundsources (I wonder how many synth's I can connect, by using a midi patchbay?)and at the same time using some softsynths as extra soundsources.
Then OMB uses cakewalk.ins files, which is great as I have an INS for each synth I own..and I don't wanna write new ones..
Chord recognition..
Drag and drop functions (very handy with loops)
Also runs on relative old PC's, which basicly means that the software is written well!
Jos is Dutch makes it easy with technical questions...

I don't have a yammi, but above mentionned utilities are enough to buy the software
Will certainly try out when I am back from a short vacation...(I leave wednesday)

Thanks,
Fred