I only tried a custom one time (InEarz company), and I had problem with fit and I really don't like the sound signature.
I tried almost all the iem's in the world.
Now I have one Westone UM Pro 50, one Sennheiser IE800, one Shure SE846 (with Brimar cable), one Aurisonics ASG 2, one FitEar F111 and one Phonak Audéo 232.
I hear a lot of people telling me I need to go to the custom and now I will try again, but I don't know if I will have the WOW effect that I really want. Hear the instruments in my front or my back, the minimal details.
My options are: JHAudio (a lot of people told this is a neutral/flat iem), FitEar, Unique Melody and Westone.
I tried don't get the highest model, because I spend a lot of money with this stuffs in a short time. Only the Miracle and Westone ES60 I'm willing to pay.
If someone have any opinion, I appreciate.