I love them, the memory foam, the metal, the way they fit, honestly not sure why I waited so long to get them. I did see your mod, but I use them mainly with the ZO and they pound, not sure if your mod will help them extend lower, but at this point with the cups vibrating not sure what I can possibly gain? Since both my ZO's are out of commission ATM (v1 headphone jack only does right chan, and v2 being updated to rev.3) I have been using the SRS iwow (iPhone/iPod LOD plugin) and it does the job, just a tad bright sometimes. I also got a 3ft. Black dragon cable (as the coiled cable for portable use is a bit too much), I have noticed a bit of an improvement but not that much, then again, I've only had about 20-30 hrs burn in on it. In hindsight, I should've gotten a double helix cryo copper one, as at the same price: it looks better and is a lot more flexible, then again, if I was handy I could've just put together a mogami cable, but I am not :/
On another note, just received the AKG K550, and first impressions out of the box, they are way too bright for me, however, with the ZO, they're great. It was an impulse buy, and were meant as portables, unfortunately they are going back, as the non detachable cable is VERY long, and they are HUGE, I would say somewhere between the xb700 and 1000. The craftsmanship is very nice, but aesthetically, I'm not sure what they were thinking when they marketed these as portables ? And at this price, I think I will pick up a pair of MDR-Z1000/7520 instead.
Sorry to derail with the above. I emailed the UK shop (iheadphones.co.uk) about my MJ591 order being shipped, and unfortunately they have not gotten back to me as of yet, I am really hoping that they will land here by Xmas as they were meant as a gift
Am also hoping that Pioneer followed the example of the HDJ's and made these new portables as outstanding, but I am a bit worried, as the HDJ 2000 were a lot more than $300 msrp when they were first introduced and of course can be had for a lot less now, so not sure what that says for the MJ591s.
Not sure if you are aware/ a fan or not of the Digizoid ZO, but personally I can no longer listen to music without it. And by music I mean primarily dnb and dubstep, not sure how well it would play with acoustic of any genre, but I would highly recommend for anyone to try it out, IF you're after some unreal bass.