I think HD UHD combi packs make a lot of sense if the film is natively 3D and 2K, or 4K and a 3D 2K version exists. The 3D is the BD, the 4K or full res 2K is the UHD disc.
I spent some time with the most expensive Sony. Can't say I noticed noise reduction problems. Probably with test patterns it's an issue, but with actual transfers? Is there some link documenting this problem? What's a three chip DCP? :D I want one too!
I prefer higher native frame rate to 24fps for "fast" motions. But then again people scream "soap opera effect". There is no pleasing everyone. Variable frame rate maybe...