After a couple of weeks of gathering all sorts of information about reference headphones in the market, I decided to go for the Beyerdynamic's DT-1990 Pro. The main reason was to add a reference listening device to my home studio setup, and I must say I'm definitely amazed by the overall quality of the product.
So here's my detailed review, after one month of relatively moderate usage (~4 hours average per day):
The build quality is very high, they seem quite durable and sturdy.
In terms of comfort, the weight is not really an issue since the materials used in the ear cups (especially the analytical ones) and the band are of very high-quality. My only concern is that, after long sessions, the heat around the ears can become a little bit annoying, but it's not a major issue since its root cause can be related to lots of different factors.
Let's move to the sound: very, very, very good.
Sound stage is huge, brightness and clarity are first citizens, along with high transient speed and good resolution. Stereo imaging is very accurate as well. Given their open-back design, they fall into the airy side and give you the impression that you're actually not listening to a pair of headphones at all, which is very impressive to me.
The bass response is very linear and distinct. No noticeable roll off even at sub-bass frequencies.
The mid range is a little bit forward, but that's exactly where the Tesla driver shines: they provide astounding clarity and speed, making mix work very accurate.
The trebles are also very accurate and clear; the only thing to notice in this range though is that there's a noticeable peak at around 8.5kHz, which can result in highlighting sibilant sounds; when it comes to mixing, this could be very useful (since it helps in spotting issues e.g. with vocals or acoustic recordings), but from a pure listening perspective, this could cause some annoyances to very demanding audiophiles.
Given their price, I think it would need to be doubled in order to find something significantly better.
No need to mention Thomann's celerity, super fast delivery times and great customer service!
Short recap: if you need a pair of reference headphones for your home studio and those are in your budget, definitely get them! You won't regret it for sure.