I am in the same boat with 5 headphones. I am going to keep 2 and sell the other 3 (actually I got rid of one already). Rather than looking which ones complement each other best, I've decided to keep the 2 that I listen to 99% of the time even if they are very similar. For a long time I considered keeping more and enjoy the complementarity but I very rarely reach for the other 3 and when I do I quickly swap them for one of my preferred 2.
The only thing that stops me from selling them now is that I'd like to write a review before selling them if only because I have been looking for a comparison myself before buying them. And I'd like to sell them to buy my next pair.
All this to say that ranking your headphones by decreasing time on your head should help you reach a conclusion (either way) much faster.
And I second haroT3k, let us know for the DX1000
