As best I can figure out, we seem to have seen the British cut at Beyond Fest last night, on a really lovely 35mm print. If someone can point me to a definitive moment that only occurs in the British cut I could say with more certainty, but it definitely wasn't wanting for pubic hair and
there were a good few (disturbing) close-ups of Reed's crispy, well-done face at the end, to go off of criterion10's notes above.
What seemed like coy evasiveness on the programmers' part in the lead-up to the screening actually struck me as delicately-worded legal maneuvering in person, as the programmers were seemingly unable to say precisely which cut was screening even immediately prior to rolling the film (they kept alluding to what they were "allowed" to say about this version). I'd be very curious to know the circumstances that made such a screening possible, especially if, as has been suggested, this was the cut that has never/rarely been screened in the US (they did hold to the notion that this was the third US screening of the print, ever, and even cited the locations where it had previously been shown, but I can't recall them).
After the film, they screened the clip from "Hell on Earth" that included the "Rape of Christ" scene--insisting that "nobody tell Warner Bros." we were watching it. Not ideal quality, of course, but still great that they thought to show it, and on the big screen, no less.
All told, it was a pretty incredible experience, regardless of which cut was shown. A powerful, troubling, exciting film. I'd love to see this get a definitive Blu-ray release.