From the IMDB:

The infamous workprint briefly resurfaced, by accident, for a one-week engagement (1/15 - 1/21) at the Seattle, WA Landmark Egyptian Theater in 1999. However, this print was the one-of-a-kind 70mm blow-up, directly from Warner Bros.' vault!

There are some additional differences (that have not been reported) between this version and the other "regular" versions:
Sound was mixed in 6-track Dolby Stereo, and contained numerous differences in sound effects, music, and dialogue as compared to the standard 35mm 5-track mixes.

Opening shots did not include close-up and subsequent pull-aways from Holden's eye as he looks out the window, it simply cut closer and closer to the Tyrell Corp. building until the interior could be seen. All the while, air-traffic control headings can be heard being issued during the sequence (it was originally edited to suggest a view from a spinner as it flies toward the Tyrell Corp.).

After Leon fires on Holden and Holden crahes through the wall, hitting the table, the shot stays on Holden as fan blades brush his hair and his back smokes from the gunfire.

Deckard's meal at "THE WHITE DRAGON" can be seen being laid on the bar in front of him, rather than merely being heard.
No narration during the scene where Deckard awaits a seat at "THE WHITE DRAGON", but the blimp's advertisement is un-altered in the background (unlike in the "Director's Cut", where it WAS altered to cover the narration over).

When Deckard and Gaff inspect Leon's address and the attendant opens his room for them, he says, "Kowalski", indicating the current tenant. Kowalski is Leon's "last name".

Roy does not ask Chew, "Now...where would we find this J. F. Sebastian?"; the scene merely cuts to Deckard driving home.
When Deckard plays the piano in a depressed stupor: a) there is no unicorn vision, b) there is no background music, and c) we hear the one or two notes Harrison Ford actually played on the set.

Deckard's search for Abduul Hasaan lasts longer: we see more of Animoid Row and the back streets of the sector.

After Zhora attacks Deckard and flees, we see Deckard loosen his tie from his throat...as if he was nearly beheaded!

"If I Didn't Care", by the Ink Spots, was originally heard in the background when Deckard purchases a bottle of Tsing Tao.

In Deckard's apartment, there originally was no "Love Theme" as we all know and love; the initial music track merely continues on longer. Also, Rachel plays a different selection on the piano when testing herself; it actually was the sheet music we see displayed!

When Roy kills Tyrell, the footage of Tyrell dying was more in tone with the International Version (yet still somewhat tamer) and Roy then turns to Sebastian saying, "I'm sorry, Sebastian. Come. COME", as he stalks J.F.

Bryant's info to Deckard over the CB about Tyrell's and Sebastian's deaths are heard as we see Deckard driving through the tunnel.

When Deckard is parked in his sedan on the street, he is merely preparing to call J.F.'s apartment before the police spinner interrogates him.

We actually see Roy break Deckard's fingers, in close up, with a prop-hand.

More shots of Deckard as he hangs on to the nieghboring building for dear life, after "jumping the gorge".

Different, farther-away shots of Roy as Deckard watches him die.

Alternate narration was placed here (the only narration in this version), which consisted of this: "I watched him die all night. It was a long, slow thing and he fought it all the way. He never whimpered and he never quit. He took all the time he had as though he loved life very much. Every second of it...even the pain. Then, he was dead."

No shots of the "rolling TV monitors" in Deckard's apartment as he searches for Rachel. The shot merely continues, close up on Deckard, from the opening shot of the sequence, until he reaches down to pull the covers from over Rachel.

No end credits, merely exit music: the same cue heard as Gaff takes Deckard to see Bryant at the opening.