I'm using the T4s for about 1 month now and while the headphone itself really rocks (I can only compare them diretly to the Shure SE215, EOZ Air at the moment, if we are talking about in-ear VS in-ear), the cable is a weak-point Tin audio HAS TO FIX!
If you take a look at the Indigogo page for the T4s you will find a whole lot of people having the same problem: one or both sides randomly cuts out. And yes, I had the same problem. Fortunately, the Linsoul support is great and they sent me a replacement calbe which arrived in Germany about a week after my complaint.
And what should I say: they are nice enough to send the Tin T3 cable which not only works totally fine, no it also is better build and not so annoying "sticky".
All in all I would absolutely recommend the hell out of these headphones (for all genres besides heavy metal, which somehow doesn't work for me with the T4s...) IF the cable wouldn't be so bad. Only if you are sensitive to "shouty" headphones, you might lookt at other options: I myself don't think they are "shouty" but I can see why people come to that conclusion.
Just to give you guys an comparison: I would always take the T4s as mobile headphones over every bluetooth over-ear I have tried so far, including Denon GC30, B&W PX7, Beyerdynamic Lagoon/Aventho/Amiron, Audio Technica DSR7/ DSR9 BT and a couple of others I can't recall at the moment.