I searched for results on flickr some time ago... and found a handfull photos of people saying it was tri-x / hp5 rated at 6400 (some of them were quite OK, some looked quite underexposed...) one single picture claiming to be a Tri-X pushed to 12800 (under daylight conditions) and several pics that are said to be Delta 3200 rated at 25600...
I somehow do not really belief, you can rate any available bw-film at 25.600 (not to speak about 51.200), use this Spürsinn stuff and get non-lomo results.... (I would be happy to be proven wrong)