Hi all.
I just spent the past few hours comparing my Primes to the Sennheiser HD – 800S's, and I am totally amazed of my reaction. Before I go into the hype, yes the Sennheiser's are amazing headphones. The soundstage, the "airiness" is really first rate stuff. But the thing is, the Primes are amazingly close in a lot of ways. In fact, in a few key areas such as percussion, I prefer the Primes by a huge margin. And as far as the depth and quality of bass, it's really no contest.
The one thing I notice is that there can be a pronounced chestiness or heaviness to human voices with the Primes, but it was really only distracting when I switched headphones.
Again, the Sennheiser's are clearly superior, especially when it comes to detail retrieval and headstage. But the Primes are just so close, so ridiculously good at what they do, that it's easy to forget that these are closed headphones. In fact, I can't really say that one is superior to the other. I think it depends more on my mood than anything else. Sometimes I want the detailed finesse of the Sennheiser's, and other times I want the full throttle experience of the Primes. Chocolate and vanilla: I think I like both!
All in all, the Primes are looking like one of the better investments I've made in this hobby. Every now and then I think about upgrading to one of the Ethers, but after my experience tonight, it's not something that is going to happen anytime soon.