I agree with Dillan as well.
I owned the Focal Utopia for several weeks, and compared it with my modded HD800 and a HD800 S, and sold the Utopia.
The Sennheisers are simply airier, detailed, and more open than Utopia to my ears.
Soundstage on 800's is considerably better.
Now, the Utopias do have better dynamics, more punch, and a stronger bass overall, but to my ears they are a touch too dynamic, too forward, and have a claustrophobic "in your head" sound to me, and an unnatural emphasis around 1.5 khz (sort of a "honk" coloration), and some sort of slight beryllium metallic coloration that I can hear.
They do have more precise imaging than the 800's, within the Utopias smallish soundstage, however, if that makes sense.
I drove them with an Oppo universal disc player, Marantz CD6006, Beta 22 with Sigma 22 outboard power supply, an Auralic Taurus Mk.II, and tried out a Schiit Gumby DAC, and a Furman line conditioner, with them, so I was using good equipment.
Maybe I just hear differently.
Don't get me wrong. The Utopia is a great headphone in many areas, but simply overpriced, imho.
Never the less, I really wanted to love the Utopia and sell off my other cans to justify the cost, but could not get past it's slight weaknesses that were deal breakers to me.
In the end, I kept the 800's and HE-6's, and don't regret it at all, and saved quite a bit of money.
To each his own.