I think I'm going to return mine for exactly the same reason. They start off comfortable but after 15mins or so, you notice them sat in your ears and it's quite distracting.My AP3's are going back today also.
I wish they'd kept the bulb size down a bit.
After several days of usage, I never really enjoyed the feeling of having them in.
The sound was great, but if I don't like how they feel, it's the wrong product (particularly since I have AP2's already)
I can leave AP2's in my ears and forget they are in there.
AP3's -- I was always happy to take them out. It wasn't "awful", but never did I forget they were in there.