Richard_stacy, I have used the ER-4P since 2000 and keep them at home since the HF-2 came out. They both sound great with my iPhone and I really like the microphone and "button" on the HF-2 for talking and working out.
There is a newer version of the HF-2 coming out soon that will have three "buttons" on the mic for volume. I will probably get them because I use workout a lot and like having easy access to those controls without reaching in my pocket and looking at the screen. Most Apple Stores carry the HF-2.
One thing I can highly recommend is trying the different tips that come with the Etys. This makes a big difference in sound quality and comfort. Everyone's ears are different, and you want to make sure your have a good seal, while still being comfortable.
There is a newer version of the HF-2 coming out soon that will have three "buttons" on the mic for volume. I will probably get them because I use workout a lot and like having easy access to those controls without reaching in my pocket and looking at the screen. Most Apple Stores carry the HF-2.
One thing I can highly recommend is trying the different tips that come with the Etys. This makes a big difference in sound quality and comfort. Everyone's ears are different, and you want to make sure your have a good seal, while still being comfortable.