The apple earbuds sound a little bit hollow. I would say the EX600 sound pretty close but the headset apparently outperforms the EX on some tracks I listen to. For listening to music for a long period of time like I do , I have to say the earbuds provide more comfort than sealing the ears for 8 hrs everyday.
You're getting a bad seal. Don't blame the earbuds for bad sound if you can't put them on correctly. It's misleading.