BYG releases on Fuel 2000 & Sunspots

I know Fuel 2000 has re-issued a couple of BYG label titles lately (Sun Ra, Don Cherry, Art Enseble & Archie Shepp) and a label called Sunspots has as well (Sharrock and Silva I think). So far they have released different titles so all was well and good. However, now I see listed a single disc release of SUN RA: The Solar Myth Approach Vol. 1 on Sunspots which is currently paired with vol 2 on Fuel 2000. Does anyone know the differences as far as remastering/mixing or anything else that would recommend one over the other? jeff