I managed to get them off of someone from the Cynic forums. Just thought I'd post here to ask if anyone else has heard them. The 1988, 89 and 90 demos are merely interesting to listen to, just because it feels cool to have your favourite band's demo (plus there are ocassionally good bits). But the 1991 demo is FUCKING AMAZING! The production's fairly poor as to be expected, but the material is undeniable genius. It has, to my ears, a version of Uroboric Forms that equals the album version with ease.
Plus the Portal demo is pretty spacey and cool too.
