Let me help with the HF5s...
These iems are very special, in a way that whatever your newer or more expensive gear might be, you keep coming back to them to review your matterial and enjoy your music their way...
This is not to say they are perfect though. The major strength is neutrality and fine detail retrieval without becoming bright.
Now this is a rare virtue...you can listen to layers of music (very enjoyable with complex pieces) and at the same time the sound is so very sweet and mellow.
Voices are plain perfect. Coming from a company that designs hearing aids this is really no surprise. The gain is an extreme fidelity in human voices and natural instrument timbre.
No matter how many earphones or headphones I've ever experienced, these are top in that regard.
On the less stellar side is bass extension which I can best describe as recessed. The notes are all there, even the deepest ones, but they stay in the background, letting the rest of the spectrum express the music.
If you like a dynamic, punchy feeling that hits your stomach, well, it's not here...
Finally the recording quality is vital to the performance of these iems.
Listening to rock tracks I find pieces that sound stellar, and others sound so crap that you are forced to press FF and just go on...
Hope this helps in some way...