I'd love to see your images at full resolution to compare the images between lenses. Failing that I'd suggest you take a critical look at your images shot with your existing lenses and those shot with the L glass. If when you pixel peek you can't see a clear difference in the resolution, then I'd say there might be some gains to be had with improving technique. If you can see the difference and you feel the spend is worth the difference you're seeing, then you have your answer. I've seen great images posted with the bodies that you already have. I personally wait for a quantum leap before popping on new bodies. I shot a 1D mk2N for a long time in the face of the Mark III and Mark IV being available (toward the end, I did feel hampered by the high ISO performance).
