Hi pacman46,
I got hold of my HF2s a couple of days back. First impression was "Is this even half as good as people rate it ?" I was coming bk frm the airport and had tried them on with the default 'smaller' tips. I was not getting a proper fit, no isolation. I was on the verge of being dissapointed. After I reached home, I changed the tips to the longer ones and wow..there was a world of difference in the sound. The mid-range came up like beautifully. never harsh. Bass was good and controlled and tight. and I definitely do not regret buying these @130 $. However, these may not be the same value for money as the ATH M50 (though bass is slightly , a teeny-tiny bit uncontrolled w.r.t. HF2 and also there is no better vfm than the ATH M50). Mid range is better and about 80-85% of what't there on the HD595. Highs are a bit rolled off, but that is just fine for me. Vocals and guitars and riffs will stand out beautifully..
Also, the instrumentation separation is wonderful. I must warn you that there are many more 'fun' IEMs in that price, HF3 are meant for the purists, seeking original recorded sound reproduction....accurate.
In case you want to know something more specific, let me know.