For a first impression, they look beautiful in green. They're big but they're light, fit my ears very great.
About the eartips, I agree with
@BobJS . The stock tips don't fit the EST50s, you'll have to find the tips that fit you best (I have one pair, they fit with all of my iems, don't know why). Maybe stock tips will be good for you but not for me. And to enjoy perfectly EST50, I think you need to begin the quest "Find The Perfect Tips For You", because to me, they looks like a lot eartips dependants.
OOTB, I'm a bit surprised. I've tested a lot of IEMs and these ... They have something very, very different, the tuning is very good, when
@Dsnuts said they looks like two subwoofers when it needed (like a ... Headphone ? ), I am totally agree with him.
The first thing that appealed to me, it was the high frequencies, I don't know how to describe them for now but I am not a treble-lover and they're so good. The next thing was the bass. The quality is good and more than that you have 0 (but really) bass bleed maybe because the mids are a bit to backward ? And it's a very big point, how many "bass-focused" or "basshead" IEMs have this...
Bass looks like is the main point. I tried them on Industrial Techno, you feel them, a lot. Just for fun, I made an EQ +5dB in low frequencies, they responds well to EQ (and they just become bass-monster IEMs).
I will write a detailed review soon ! I just made a little session to get used by them, I need more time ! But damn, thank you
@Dsnuts for recommending them to me !