Koolpep
Headphoneus Supremus
Thanks keeferdog and others for your input. It definitely helps forming my opinion. I think I will go listen to them for some time, without comparing with my own Hifiman RE400's. One thing you said I don't understand keeferdog. You say that the PM-3's are very good headphones, and perfect for traveling. But...........they are not the cans to use at home listening, to the good stuff, the nice amp and good source. Why not? Which headphone would you recommend for that purpose? Basically, what I want is ONE headphone for both traveling and listening at home. Only, listening at home for me will mean using the same iPhone with DragonFly, not a fancy headphone amp. And since there will be other people around, it has to be a closed back headphone.
The PM-3 is very good - especially with a nice amp and DAC. And they can be used for home listening perfectly well. It just depends on what you are used to and what your budget is. Pair it with a Mojo or like I do with a Liquid Carbon and you are in for a very nice treat. Home listening is absolutely possible and enjoyable.
I currently have some Stax and the Focal Elear at home and a few other lovely cans, and the PM-3 still holds up very nicely. I found them boring at first listen, but give them a few hours on your head and all of that is gone, they are engaging and overall amazing headphones that I love after years of owning them. And I have a couple of "better" headphones as well.
Will open cans for the same budget sound better? Not so sure, some might, some won't. But for your use case these are a very good choice in my opinion.
Would I listen to the PM-3 at home when I can listen to elears? No. But then, different budget.
Cheers.