The SRG-01 expansion will have audio loops and 30 new styles that take advantage of the loops themselves (OS 2.0 allows the G-70 to play audio loops in sync with the styles, a la Ketron SD1 and Korg PA1 X pro )
The expansion board will also have new sounds, drawn from the Roland library, and new drum sets.
I think (hope) that Roland is finally correcting the mistakes initially done with the first release of the G-70 and coming out with an arranger keyboard worth considering.
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Korg Kronos 61 and PA3X-Pro76, Roland G-70, BK7-m and Integra 7, Casio PX-5S, Fender Stratocaster with Fralin pickups, Fender Stratocaster with Kinman pickups, vintage Gibson SG standard.