I have the T5p 2nd and I like them. They have a nice instrument separation, good speed, fair soundstage and good bass. People complain about them leaking sound but I have not had problems regarding that so far. I must say, though, that I do not listen to music at very high volumes. For me, they also have an adequate amount of treble and are not sibilant, which was apparently a problem with the first gen.
Comparing them against the Oppo PM3, the T5p is more open sounding, bass has lot more impact and are much more engaging and they are also more comfortable. Against the DT1770, the T5p are less bright, have better bass accuracy and are much more comfortable, soundstage is similar. Against HD650, the T5p have more soundstage and are less veiled, they are also much easier to drive.
I do not use IEMs due to some serious wax issues, so, no comparison available in that regard.
Those comparisons are not fair, due to the price difference, being a fair one agains the Mr Speakers AEON or something similar (Which I have not owned yet), however, I think that the T5p have a nice price/performance ratio.
Regarding portability, the carrying box is rather big, but it can be fitted inside my backpack anyway.