I've described my views on HD 580 versions widely on head-fi. The important thing is to be aware of significant differences between them. This review is about (probably) 2nd version: made in Ireland, dark driver screen, flat HD 580 inscription. These headphones are not perfect in every aspect. HD 540 for example are better as far as mids are concerned. But HD 540 can't handle rough music with many instruments playing at the same time. They are not any genre master, but for the price, I guess, it's hard to find so versatile headphones. Also, if you like sound being on the bright side, don't buy them. The sound is not dark, but definitely it's not bright either. High tones are really pleasant, present and smooth. Bass is well described and goes satisfyingly deep down. Mids are not overwhelmed and have a great timbre, not as good as HD 540 though.

I use it with Sansa Clip+. The make a great couple. V-Jays are not the best headphones out there, also in its category, but for some it can be an optimal choice. I used to have the original PX100, but as a treble lover I didn't buy new ones after they broke. They have nice Sennheiser signature though and I appreciate it. I tried Superlux HD661 but... gosh, they poked my eardrums with thousands of needles. I think many people overlook V-Jays beacause they used to cost much more than they do now. At least in Poland. Today it's hard to find a cheap alternative for them. KSC75? Nope, comfort issues. PX100 - as above. Porta Pro - too bassy for me. DT 235 - good one with an odd tonality, you can almost feel a few gaps in frequency range. V-Jays give you overall neutral tonality, pleasant treble, natural but a little laid back midrange (I'm not even sure if it's laid back at all) and really good low end. They are also fast enough for some rock music, but they are slightly better with slow one. Case wouldn't hurt. I struggle finding one on my own. I guess I'll end up with a sandwich box. You can fold them, but can't make them flat like PX100. If you like: sound close to flat, on-ear fully open construction and your budget is near 30$ they are worth a try. The only significant sound issue can be upper midrange for some. I guess this is where they "pay" for being brighter than most of cheap headphones.

My colleague owns a pair of HD 580. Their sound is very versatile, bass and highs are extended perfectly. Despite that, extreme ends never flood the mids. Whatever you listen to, they will not let you down. So I bought one too. A huge disappointment. One word: veil. "What?", I thought. The same headphones model, sound totally different. The answer is: there are 4 versions of HD 580. Germany made, early Ireland made, mid Ireland made, late Ireland made with bright driver screen. I probably bought the worst one (mid Ireland). My colleague has early Ireland version. I read some headfi opinions about HD 580 line. Apparently the oldest one (made in Germany) were the best sounding. So I started to look for them and never succeeded. I gave a try some other old models: HD 545, HD 540 and landed here with my HD 540. HD 545 are the brightest sounding headphones I've ever heard. It's pleasant to listen too as long as you don't miss the bass and good balance. HD 540 blew my mind. The highs are unbeatable, never heard better. The timbre of treble and mids is so relaxing and sweet pure joy. The rsolution is very satisfying. Bass is good. Not as good as HD 580 tough, not as extended as I'd like it to be. But it's ok. The texture of bass is well recognizable and when a song is based on bass, you can feel it does. Generally I prefer HD 540 to my colleague's HD 580. The comfort is near HD 580, not easy to compare beacause the pads are not as fresh. Both are good for long listening. I love the look. Very subtle and noble. They survived almost 30 years and are in very good condition. I thought HD 580 are light. I was wrong, HD 540 seem even ~30% lighter. I am ready to buy  HD 250 (or HD 430) pads and a cable replacement, but there's no need. I compared them also with AKG K701. The main differences: bass is very similar, K701's mids are artificial and too bright, K701's treble is dry, and unpleasant, scene is wide but undifferentiated. HD 540 has mids on the right place and uncanny timbre, scene - sometimes you hear voices near, sometimes they are further, you can notice the movement of them. I hope they will serve me well for years.