I've been listening to my T5s for a couple of days now and have to say i am very impressed. I do like them better on a dedicated amp though wich is not what they were really made for. They sound very musical and full of depth on my Concerto much like the T1s. Very neutral in sound. And due to the closed design 0 background noise.
But this should be more about portability. As a portable headphone I have listened to them on my Sony mp3 and ibasso d10. Again I found them to be a "great" sounding headphone. Not lifeless or boring. I still can't believe the price tag though.
Clearly a lot of work and build quality went into the making of these headphones. They are the most comfortable set I've ever owned. ( Hate the short cord though )
In short I don't think I would pay this much just for portable use but will use them as my regular cans as well.
Enjoy