I had an RE-zero a few years ago. Awesome and wonderful. I was extremely happy, and when I wasn't, I reminded myself how little those cost and became happy again.
They broke after 4 months or so. I sent them in, and got a new pair. The new pair then broke as well, again in 3-4 months, and I feel like I babied them, certainly relative to my other IEMs.
Same complaint--housing started to come apart and/or the sound in one side started to go.
What is the general feeling about build quality of the RE-400? It is supposed to be "better" but in the wild, are we seeing just as many complaints about build quality?