Death Industrial is more slower moving, have a distant, somewhat darker atmosphere.. It's have a more colder, and hidden anger. Power Electronics have more 'in front of' feeling, also more aggressive, facefucking vocals, and it's have more mid-high freq. feedbacks, than bass-only parts - (I think, but it's only my perception).
But another question was not really talked : production wise, what's the different between the two genres? or It's really depends on the artist, and it's vision about the overral sound, or there are some recognizable marks? I mean, the size of the space in the sound stage (I've think about reverb/echo stuff), amount of distortion, mixing/mastering, and similar thinks like this.etc:. ?