I am loving my new X1s. I got them for a song used, and they are fantastic. They legitimately do everything well. I can switch from genre to genre or movie to game seamlessly and they perform well.
There are definitely some areas where these headphones excel, and are a revelation. I find deep house music with strong male or female vocals to be a major strength. As well as 90s/early 2000s R&B and Hip Hop. Rock and Roll, oldies and alternative is also very good, but doesn't lend itself as well to the strength of this headphone. This headphone is a real treat for someone who enjoys bass in their House music and rap.
Watching movies and shows is also a treat. Burn Notice with these headphones... wow. You notice every little thing going on in the scene. You are immersed within the show. If a scene is being shot in a concrete room, it sounds like a concrete room. Same goes for any other setting. I personally love this, and feel like it takes my shows to the next level.
Gaming is also great. Massive sound stage and gaming sounds great. The sound of sniper fire coming close to you in BF4 is really something to behold. It sounds so good, and its like each shot has its own signature based on how close or far away it is. Really impressed with this and has taken immersion in my games to the next level.
The only area where I find them to not do so well is with more pop-scentric music. Songs and artists that take full advantage of auto-tune, it seems to throw the entire track "off" for me. Its not bad, but going from a poppy song where I am noticing this irregularity, for lack of a better word, to a house song, its a massive perceived difference for me. This is not a complaint, just an observation. I am very pleased with these headphones and I would recommend anyone to pick up a pair used if they can get them in good condition and at a good price, say $120-$180.
I opted for these over the X2s because the X2s were on back order, and have the mysterious dye leak issue going on. Not to mention, paying twice as much for some small, but noticeable improvements. Maybe the X2s make those auto-tuned songs sound better?