so i bought them last weekend; very happy with them. got the master tracks xc, the red ones "tuned by calvin harris" (though i wonder how involved he was - could have just slapped his name & face on it after it was tuned by anyone else who recognised the regular master tracks are too muddy & bassy).
anyway, they definitely are much better than the regular master tracks. i still wasn't allowed to sample the xcs in store (hmv), so spent a good 25 minutes sampling the regular ones with my own music; basically to confirm for myself where i thought they were lacking (or consider whether i'd been too harsh on them the first time). i don't know much about headphones but i've had a few sound systems in cars, and the regular ones sounded like a cheap 12" sub-woofer in the boot. very capable bass, but totally drowns out everything else. it seems like the one token attempt to compensate was simply whacking up a simple "treble" dial by a few degrees. the mids get lost, and vocals often came out a bit tinny.
the xcs on the other hand, sound like a decent 10" sub (in my car analogy). perhaps can't reach the impressive rumble-the-windows-of-kfc-as-you-slowly-drive-by but they've had a much more pleasing (to me) punchiness with all the genres i've thrown at them so far. i'm coming from cheap in-ear ones so i'm more than happy to have any bass at all.
the mids are great. in comparison with the regular master tracks, the mids are actually there. of course they sound great with anything electronic, dance music, but i'm so relieved they capture everything in all the rock music i listen to. anything produced with half-way decent production values in the studio sound great, but i'm more impressed with what the xcs found in slightly-crappier-produced music. oasis' first album was not made with the biggest budget and has always sounded 'less' than their later work, but these headphones made it sound way better. bass was there, rhythm guitars were crunchy and clear, and the vocals stood out plenty. very impressive.
earlier stuff like iron maiden, kiss, david bowie; all sounded great, although the albums of theirs i have have all been remastered at some point, so already had a head-start. can't complain though, 30 year old classics sounding like they were recorded yesterday
the first music i put through them was dutifully calvin harris' last album. predictably sounded great. like i said, anything electronic sounds amazing. drum & bass was punchy, dub step (don't shoot me) was suitably distinctive, mixing deep rumbly bass with high-pitched effects and screeching. pendulum was great, mixing a lot of heavily produced drums and bass with guitar work standing out clearly. hip hop & rap very enjoyable, though with rap i still reckon the treble could be boosted a tiny bit more (mainly for vocals) but to be honest i can tolerate the effort to set an eq setting somewhere in itunes for that.
quiet piano was fine, if not brilliant. ludovico einaudi, christopher o'riley, both mix piano with a bit of light orchestra, with the latter often starting delicate and light, and ending up thundering up and down the piano with a big epic sound, which the xcs coped very well with. the lighter moments could be a bit less muddy, but again i don't mind fiddling with the odd eq setting here and there. i reckon i can't complain considering how good i find them elsewhere.
big orchestra: movie/game soundtrack sound fantastic. i reckon the best genre i've thrown at them (slightly odd considering they're supposedly tuned for electronic dance producers, but thanks anyway calvin harris!). harry potter scores, lord of the rings & the hobbit, halo 4, all presented perfectly, from tiny moments of hovering violins to massive explosions of full strings, brass, with plenty of percussion. i feel like an idiot gushing about them but it did occur to me that i felt like i could hear every instrument.
well worth £60 over the regular master tracks. wouldn't even consider those. they just don't work, unless you want your bass to flood out over everything else. these are more neutral but way better balanced, which means they suit a huge range of music.
i prefer the matte gunmetal grey finish of the regular ones over the subtle red xcs, but they still look fantastic nonetheless. no tacky branding other than the sleek sol republic logo on the cans (calvin harris written on the inside of the headband, nice touch). two cables to plug in (one each per can) which i understand is less preferable to djs, but that doesn't bother me. i used to hate accidentally tugging on the cables of my in-ear phones; as i like to run the cable inside any coat or jacket. the cables attach to the xcs' cans very securely; you'd never tug them out, and for that, they're infinitely better and more comfortable.
i had them on for a good hour yesterday each way into town and back, and they were very comfortable. apart from a slightly sweaty ear (are my ears unhealthy? do i need to go to an ear gym?) they were perfect.
one thing: because of the way they sit on the headband, if you take them off your ears to hang around your neck, the band naturally tightens so the cans don't sit on your collarbone, they bunch up right under your chin. they're not small cans either, so i felt a bit uncomfortable, but i didn't buy them to be a necklace, i bought them to sound good. which they do. hooray.
most expensive thing i've ever bought without trying, but i hope this helps anyone else thinking about these.