I have both the 650's and Audeze LCD X's. No comparison, the X's blow away the 650's in my opinion. Of course at 5 times the cost I paid for the 650's, the X's are in my opinion the go to headphones paired with the Hugo. The detail and stage presentation are like being there, Live.
What I love about the Hugo is that in combination with quality cans such as the X's, you probably equal some of the best sound systems in any combination on the market today and all you need is two pieces along with your PC/existing play back device.
So for roughly 4K you've got reference sound second to none? Simplicity and quality, two of my favorite objectives.
I see. I've heard they're good but they're not sold in my country. Besides, people say they are big and heavy, might be big for my head.