I for one had no problem finding the perfect fit right away, with Sony hybrids. No comfort issues really, isolation and seal were so good, the cable was amazing, bass...well coming from RE0 I knew what to expect; sound blew me away anyway...
The thing is in a matter of minutes the left earpiece caused me so much pain that the ear canal, the outer ear and eventually the left cheek started to hurt. The right earpiece just disappeared, the left one gave me hell.
I had to set them aside until the pain subsides.
Now, everytime I fetch them from the pouch, and I wrap the cable around the left pinna, I can sense my ear canal tightening as a pavlovian reaction triggered by the anticipation...you know, like when you see a needle and suddenly your buttocks throb with fear
This is exactly what happens to me actually (except it's my right ear that hurts). I don't have any issues with the tips, I have hybrids, comply, and tri-flanges to choose between. It's the housing or the angle of insertion or something, but after a while my right ear starts to hurt an insane amount and I have to take them out and use my westone's instead.