Hello SCP,
as I said in my earlier posts, I am still using the original Version 3.30 released on 27.09.01!!
I have not upgraded to OAS6 yet due to lack of time but I will probably do it some time in the next month.
So I can comment on the sounds I already have installed and from these the best of course are the Long Waves i.e. the stereo samples from the hard disk.Most of them are very natural sounding with a lot of detail and velocity crossfades (multisamples).Among the best are IMHO the Grand Piano, Accoustic quitar,and most of the Brass & Reeds, including also lots of accodions.Choirs and Human voices are excellent.There are also many full pad sounds.Its difficult to find a 'not good' long wave sound.
Unfortunatelly these sounds cannot be used in the styles/sequences in versions prior to 4.0 so I cannot tell you how they sound in that context.I can tell you that using layering I have very real sounding Big Bands,jazz trios,etc..
The organ sounds come from the built-in OX7 'Organ Expander' that uses a DSP chip to (re)create mainly the sounds of older Wersi models and those of the B3.I feel that the (NI) B4 is much more close to the original.Drawbars can be used in realtime or saved as presets.For GM sounds in this version,an extra sound card was used with about 600 sounds available but these do not come any close to the LWSS.This card is not used anymore after v4.0 so there is no need to say anything else about it.Other sound options are loading AKAI samples ,using soft synths or extrnal MIDI devices.There is no sampler available (yet?).
The ergonomics of Abacus are very good:big touch screen in the center,lots of big user porgrammable buttons for selecting sounds on one side -for styles/sequences on the other and big drawbar-like volume sliders.
A style/seq can be mixed live ,while you play and saved without interrupting you playing.To edit notes or to create style/seq from scratch you have to used either the (factory preinstalled) Cubasis (or any other windows software.I also use EMC Styleworks for initial conversion of styles. Most of the programming is done using Touch Screen and the jog wheel while the the othjer controllers are mainly used for live playing.
I hope I will have my instrument updated soon to answear also your OAS6 specific questions.