i believe i have experienced this with my former Master, although He was able to remain tightly focused, whereas when i entered subbie space, i would enter an almost dreamlike and very passive state that He would pull me out of when it was over. but i witnessed what i felt was my Master being in "Dom space" when He had me tied to a chair and had placed clamps on me and was proceeding to apply clips here and there...i looked at His face, and He actually had the same look of a painter or sculptor when they are deeply concentrating during the creation process...but it was something more too...it was a look i had never seen before in His eyes, with threads of sheer lust and i know this sounds funny but an almost pure EVIL...if i hadn't trusted Him so much it might have spooked me.
i actually did not realize until now that there was such a thing as "Dom" space. thank you for posting this.