The Director's Cut of Scream contains about 30 seconds of footage cut which would have earned the film an NC-17..
We actually see Steve's guts tumbling out of him. The steadi-cam shot up to Casey's body is about 50% slower. It takes it's time going up to Casey instead of rushing up. Tatum's head is a bit squishier. Kenny looks up at the killer after his throat is slashed. When Billy and Stu are stabbing each other, we actually see a few more stabs that we only hear in the R rated version. We see a puddle of blood that's dripping off Stu's hand as opposed to just hearing it drip.
Pretty sure that's it. It may only be 30 seconds but it is Wes' preferred vision. Also, once you've seen it, it's hard to go back to the regular-- especially during the climax. You can just tell stuff is missing.
In the US there was a widescreen laserdisc in the summer of '96 released. The Kevin Williamson and Wes Craven commentary comes from that laserdisc. So, even though they talk about how what they're watching is the Director's Cut, the viewer of the DVD version sees the R rated cut.
Someone at Buena Vista Home Video (at that point) pulled a fast one and released a full screen version of the Director's Cut on VHS. Only if you get the VHS w/ Neve, Courtney or Drew's face did you get the Director's Cut. The widescreen and commentary VHS (yes, they actually made a commentary specific VHS) contained the R rated version.
But, the version w/ the 3 ladies' faces were not promoted as Director's Cuts and they were tagged with an "R" rating. So, it was done in secret.
The Director's Cut has been released on DVD in regions outside the US, though. Apparently a German Blu-ray also exists but due to German laws can only be sold in stores and not online.
It doesn't matter whether the gore makes the film better or not-- though I would argue it does. It's what Wes prefers the film to be and what he wanted to put out in December '96. I should specify that I'm not some gore hound, either. I stopped watching the Saw films at 3 because they were just hitting me too hard. Guess I'm getting old. Ha. But, in Scream the cut gore is pretty minimal. I've found (since first seeing the director's cut) that certain moments in the R rated cut are obviously hacked. (Spoilers) The first missing bit, Steve's guts falling to the ground, just doesn't flow as well as it does in the Director's Cut. In the R rated version it's as if there is a jump cut to a static shot of Steve dead because the moment he's dying is completely cut out. It makes a powerful moment rather cheesy when you know what should be there. Also, Stu's puddle of blood in the kitchen at the end really goes a long way in selling how unhinged these characters are and shows the real effects of the violence they're doing to one another.
It really annoys me that there is still no director's cut available yet. Sure, 30 extra seconds of gore don't add overall to the movie experience..but the very first time I saw this was in 97 on the unrated VHS...watching it again years later on DVD I noticed something was missing with that opening scene. It just didn't have exactly the same impact as I remembered.