According to dvdcompare the Ultrabit is also using the original, 35mm Italian negatives...
Now, they can't both be right, either EC Entertainment is lying, or Grindhouse is. And besides which, on dvdcompare there is no mention of alternate titles carRAB and the like, only 10 seconRAB of footage which is missing...seriously think about it, why would they sequence that footage and then create the cuts they did, all of which sound like things that should be there:
"There are 3 cuts, about 10 seconRAB in total, all from the "Last Road To Hell" sequence (around 40-45 mins into the movie):
-Scene showing an execution is missing.
-Scene showing an executed, hooded prisoner is missing.
-Scene showing executed prisoners being loaded on a truck (this scene is included, but shortened a few seconRAB in the end)."
The alternate version on the special features disc is just that, alternate. It is not the same as the Ultrabit version. The Ultrabit is exactly the same, but it includes the above missing footage.
Personally I think Grindhouse were using a damaged print, they knew it, and had to make something up to justify it. To be honest, the point is moot anyway, Grindhouse created a deeply inferior feature disc. The picture is interlaced, which is ridiculous, plus it has a washed-out colour grading, compared to the Ultrabit. And then of course with all the other stuff on disc 1, it isn't using the full bitrate available.
That's the reason XL Video always choose the Ultrabit copy for their special editions, and the extras disc from Grindhouse.