Im gonna have to go with Abnegations piece. They are both amazing tags but im a sucker for rough imagery. Sorry I cant give a detailed vote but Im rarely home these days.
Edit: As I said before this really did come down to personal taste, Rest's piece is amazing and everything works so well in it, though like Abnegations piece I think there isn't enough contrast in terms of knowing where to look. The colours seem very vintage which works well with the stock in Rest's piece, and altogether contributes to a very good tag. However I do like Abnegations for the fact that it's so rough and 'abstract' I guess you could say. This experimental stuff really gets to me and while it does seem a bit clumped, personal taste gave Abs my vote.
Voting for Rest. One of the best tags I've seen in a long time. Maybe not technically perfect, but very original style, great colours and overall very fresh.
Gav has gone for the sort of grunge / watercolour look, which for me wasn't executed as well as I know he could've and feels pretty low quality. Not feeling a sense of cohesion, little bits of depth, but not enough to really bring it together and I feel that the focal doesn't match the style of the rest of the piece. You've got quite a clean vector-ish focal with the complete opposite style effects / background. I think if it was cleaned up a bit, remove a lot of the textures which are smothering the foreground, it would dramatically improve, but Rest's piece is damn strong in composition and originality alone.
I'm voting for Rest. I love the vibrant range of colours used and just the overall composition of the piece, it's the most eye-catching of the two, in my opinion. Abnegation's is nice too, I have to say the text is very well done as opposed to what people would usually do, although, I think Rest takes the win here.