I'm not sure, I actually haven't heard it yet, aside from the King of Snake/Winjer segue which is obviously different. I look forward to the digitization and doing an A-B comparison then.
Regarding early versions, there's also this similar looking promo cassette, where the Discogs notes say that they ARE, in fact, slightly different from the final mixes. I don't know if that means just slight differences in mastering or something more substantial. I'd love to get my hands on that one also.
https://www.discogs.com/Underworld-U...lease/14205638
There's also this KoS acetate that says it's an unreleased version:
https://www.discogs.com/Underworld-K...lease/16489218
And Mark has a different acetate that has an extended version of the Barking mix on it, that we'll get around to cataloging and digitizing at some point.