I don't think Apple supports 2.5k resolution as an acqusition format.
Some talk on it here.http://forum.blackmagicdesign.com/viewtopic.php?f=2&t=26765
I have the BMPC. My camera came with the latest firm-ware, and has no FPN problems, and has no noise when shot at 200-400 ISO. You can shoot low-light at 200-400ISO and boost the image in post ProRes or Raw and it will look very nice. The high light and low light recovery in Raw is crazy.
Here is one sample of low-light to show what can be achieved at 200ISO with decent glass in horrible available lighting. https://vimeo.com/96297619
I think people bash this camera because they want an awesome look from inexpensive lenses and are too lazy to use lights. I come from a studio photography background. I shoot fashion and beauty in NYC. I am very comfortable using lights and the emotion they create. Those who bash this camera IMHO probably have a reality show aesthetic and want to film plein air style with available light. This camera climaxes with decent light.
I was little frustrated when I first got the camera, because I did not understand the beauty of the BlackMagic sensor or system of cameras. But as I am learning the BlackMagic system, this camera continues to surprise me what it can do.
The global shutter produces a very elegant image. The skin tones out of camera are drop dead gorgeous, and the detail is out of this world. So many people are sleeping on the BMPC4k/BMCC2.5K Don't be one of them.
I am very happy with my camera and the images it creates = $$$.