People are reporting a size of about 10 GB for each of the three original films from Cinemax. The highest number I've seen quoted is 12 GB, I think -- and who knows what all that includes; there's some "bonus material" that may be included in that total.
The real pain is 5C encryption, when applied (i.e. often). Haven't seen that anybody has broken that. DVD Jon, where are you??
No matter: in six weeks, when Sky broadcasts the OT in HD, all will be well. Sky HD and Premiere HD are both considerably better than anything available in North America, anyway.
Ironically, very soon the only people not able to capture and watch American movies in HD, will be Americans.