Hello Spalding
I was afraid they would send you that one, good in its day but things have moved on.
The inconsistencies stem from the fact that the early OAS 2/3 instruments only had about 50 Long Wave Sampled Sounds, (LWSS) the rest of the voices (Particularly the styles) were supplied by a Yamaha XG card. (The more substantial sounding drums were probably the real drums, which are recordings of a live drummer playing a real drum kit)
There is no comparison between OAS 2/3 and OAS 7; hopefully they will soon be posting some OAS 7 demos.
Until these are posted, please keep an open mind.
Enjoy whatever you play.

Bill