I think your tune is very well mixed. I liked the little percussive elements going on near the sides. It's very pleasant as it is.
If you don't want to open yourself up to a vocalist (a sentiment I understand) then what about dropping in some interesting spoken word fragments? You could build up a concept that way, something to go with your really cool track.
It's fine, however, just the way it is. Sadly, it reminds me of Pet Shop Boys if they did instrumentals, which they very well may have, I dunno, never got on much with them.
cool track all the same.
-Tom