This is a great thread as I have or had most all these headphones. I think the z1r, utopia and he1000V2 are my top favorite. All for particular reasons and doubt I would ever sell any of these cans.
My wife's favorite is the z1r's as she has a pair too
once I told her I ordered a pair she wanted a pair too. Her pm3's don't get much time anymore albeit a good affordable planar closed back.
I think utopia's sound incredible, the z1r's are most fun and get the most time. But the he1000v2's are very balanced all around and I've had my longest listening sessions on the the he1000v2. He1000's are most comfy of the three. Hd800's are comfy too but feel the cheapest of all the headphones. I guess I could sell my hd800S and not really care too much. They are good but don't compare to the other three cans I have.
I agree with many of currawongs comments on these cans. Personally I can't really say any is a perfext pair. But I may lean to the z1r as the most practical and fun. Closed backs surely are important if you don't want to disturb others around you and.... don't forget they isolate outside noise so they have their benefit if your environment is noisy. Plus the z1r's don't fall far behind any of these headphones. They simply are a ton of fun even with the color they have. I think their bass is most impressive and maybe the ultimate bass head headphone without question! Their drivers are just massive!