I finally decided to take the plunge into a really nice set of headphones - my nicest set previously was a set of $60 Sennheiser HD 429's. While those were decent, they didn't come anywhere close to some of the high end cans that I had tried and I got tired of being disappointed every time I listened to music or watched a movie with them. After months of shopping around online and reading reviews I decided to visit a music store to try some out. After all my due diligence I had settled on the Audio-Technica ATH-M50S but I didn't buy them at the store since I knew I could get them online for cheaper. Well, when I went to buy them here on Amazon I read through a few reviews and saw Beyerdynamics mentioned over and over again, and after reading a lot about them I decided that I wanted to spend a few more bucks and try out the DT-990 Pro 250 Ohm. It was a bit of a risk since I hadn't tried them in person but knew I could return them if not happy with them. Well, they showed up today - in fact I'm listening to them right now - and let me just say that as soon as I finish this review I'm going to buy another pair for my wife.Bottom line: WOW! The sound that these headphones produce is the most open, deep, detailed, crystal clear sound that I have ever heard. I was a bit concerned about the 250ohm rating at first because I didn't know if my gear would be able to drive them without an amp, but both my PC and Oknyo receiver can power them with no problem. I do have to crank it to about 80% of max volume on my PC to get the sound level that I want, so I'll still probably invest in an amp to be able to drive them at a lower level for cleaner sound. I also want to be able to use them with my wife in the theater room after the kids have gone to bed and I'll need a multi-channel amp to do that. But holy cow these things have low hitting bass, the midrange is tight and crystal clear, and the highs are powerful but not overpowering. They are very well balanced. So far I've listened to some rap/hip-hop, metal, emo, classical, and even opera, and these things shine with any genre! I am so excited to watch a movie them. I really like the open back and I think that'll be nice when watching a movie with the wife so we can still talk to each other without having to completely remove the headphones.These are worth every penny if you're in the market for a nice high-end set of headphones. The only drawback is that you can clearly hear everything that you're listening to on the outside due to the open back, and I imagine they won't block outside noise very well, but I just plan to use them at home in a quiet environment like my office or theater room where it won't matter if they leak a little sound and there won't be any ambient noise to worry about.P.S. Forgot to talk about comfort, which is OFF THE CHARTS! They a have nice furry covers which are extremely comfortable, the clamping pressure isn't too tight, and I FINALLY found a set of cans that has openings big enough to fit my huge ears! With the M50S that I was going to buy my ears hurt after demoing them for about 20 minutes, and the clamping pressure was pretty tight but I read you can stretch them out to improve that. But I've been wearing these straight out of the box for nearly 2 hours now and just took them off and I don't even feel like I've been wearing anything. That is so much better than the normal 5-10 minutes of aching ears after taking off pretty much any other set of headphones that I have ever used. So if you have large ears or a big head these are perfect for you!