Yes, inking it would ruin it.
I adore good pencil art... and I swear it is a dying breed. I myself produce very little of it nowadays... because it is often easier to just slap some ink on a picture and call it good. However, this... it too good to be true. I do hope ink never touched the paper on this.
Incidentally, you might want to consider rounding the chin of this person just a wee bit... it's so square-ish it almost makes the image feel boxy... but then again, it matches the style used... hmm...
...either way, this is wonderfully done.
Yes, it would be a crime to ink this one. Love it.