Well you are correct on both points. First, I still have fit issues with the er-4s, but I am getting better at getting the proper fit more often. However, I still fiddle with all of the tips except the big black foam cylinders, which are my current favorite. They fit every time, but they seem to have the "slightest" (and I mean slight) bit of sibilance with them. The triple flange don't. But they improve the bass a very small amount and are comfortable, major isolation and fit perfect every time.
I love the triple flange and mushroom tips, but both require a lot of fiddling to get the correct seal. The HF5 had too much treble softness for me. It is an excellent phone for the price, and I think I reflected that in my reviews, but I wasn't very good at getting a proper fit, and when I did the sound just wasn't as open and airy or flat in the bass response. So it wasn't worth the fit difficulties to get that sound. I'm a sucker for high frequencies more than bass. But I do love my bass. The ER-4S fixed both issues and sound simply amazing, but the fit issues are not completely gone. I am better at it though, a lot better. Especially now that all the tips are softening a bit they are easier to fit, but still require fiddling for a while. Mostly for my right ear.
I can say that I probably didn't honestly give the HF5 tips long enough to break in. And in that regard I may have had a similar experience with them fit-wise, but sound-wise the treble killed it for me. Don't get me wrong, the treble was excellent, but didn't extend high enough at a flat volume for my taste. It was like everything had noise reduction applied a bit. Air (literal air) was not as apparent and strings, while smooth and bright, didn't have that incredible micro texture you get with more treble extension.
Ultimately though, I opted for the custom molds for exactly that reason, the fiddling. I want to put my tips in and forget about them. If there were no customs I'd still keep them no questions asked, but the fiddling does get old. I'd probably just buy a boat load of foam tips and be done with it. However, I'm hoping the customs sound at least the same but improve the fit process for me. With the foam and er-4s i sometimes forget they're in my ear and literally have the impression I'm listening to speakers. I love it. :)
Edited by luisdent - 3/23/13 at 1:53pm