The outline looks good but man does it really start to look better once the color goes in. We have similar tat's, go check mine out to watch the process of the color going in. I still have 2 more sits to go. Good luck and as always ROCK ON
-jamie-
cool piece! my opinion is not to leave it just the outline because it looks unfinished... at least shade it black and grays if you don't want to do color, but i don't think you should just leave it like this.