Cheers guys :)
@Garfield - Having got the ADDAC 105 (4 voice cluster) its the same form-factor as the 104, if I chose again i would maybe go with the 104 instead of the 103 as the knobs and switches are soooooooo close to each other. Though, that said once I've picked and set my percussion sounds on the 103 I can pretty much leave it alone.
The wave drone sound comes from the Ochd modulating the Cut-off on the 105 (then going through Clouds reverb) weird little beast, actually thought it was faulty, though I seem to be assured otherwise by ADDAC. Something to do wih how the settings of one knob effect the others and to the point where there will be no sound, but you can get some nice results though just a lot of variables.... whether hitting it with Gates, Triggers or LFOs all change the character of the sound that comes out with the varying settings of Decay.
Enjoy your spare HP, don't rush to fill every last space, this is not like filling sticker books. Resist the urge to 'complete' your rack, its never complete so just relax.