Which is MOST Important? And why?
On this forum, sound is almost always top priority. Other aspects usually just need to be "tolerable." A more interesting debate would be to prioritize all other non-sound properties of headphones like: comfort (as you already mentioned), looks, build quality/reliability, warranty/company reputation, isolation/leakage, and design/usability.
Personally, I usually go: sound >>> isolation/leakage = design/usability > looks > comfort > build quality/reliability > warranty/company rep.
Even the answer to your question is personal and subjective. I had UE TF-10's. They were so uncomfortable to me, it wouldn't have mattered what kind of SQ they had. If an IEM is uncomfortable to the point where it's a distraction, they're not worth keeping, IMO. You can find IEM's that provide both great sound and comfort. Among others, I have the Klipsch X10i's. Incredible comfort, and great sound as well. I did replace the oval gels with Comply medium foams though. Through the use of interchangeable tips, many IEM's can be made to be very comfy.
well i think too alot of companies that offer higher end or top tier headphones or iems strive to offer both comfort and quality. obviously the lower quality of headphone or iem sound or comfort or both will be sacrificed.
Comfort wins for me. I liked the sound quality of my Audio Technica M50 but I could not wear them for more than 10 minutes. I eventually sold them and bought some Beyerdynamics. It's not the greatest sound in the world but it is damn comfortable.
LOLz, I know what you mean...
I love the sound, But am stuck between the two Tri-Flange sizes. Neither fits.
Currently testing various foamies. Time will tell.