After spending money on 4 or 5 different " very good portable" models, around 2 years of trial and error, I finally got decent sound, much thanks to guidance in this forums. I finally went for the Sennheiser 25-1 II. It's sad to see that no really great portable headphones exist, but these are very good; not a consumer design and all plastic but very good sound without being "heaven" as some people say.
I used them with my loosless files (music) and Bithead portable amp. I hope someday soon, one company goes for the great headphones. Thanks for all this guidance.