I’m a recording engineer/producer. There is no such thing as a perfect headset or ear monitor. First, each person has their own needs; noise reduction, listen to books only, isolation, comfort, open sound, over ear, on ear, weight, looks, wired, wireless, sweat, size, surround, mp3 or other decimated source, lossless source (flac, vinyl, 24 bit+), environment, folding, case, charging, batteries, durability, expense, etc., etc., etc… Different ears hear sounds differently. We do not hear things the same way. Therefore, each ear device will sound somewhat different to each person/ear. Some musicians prefer one headset over another in the studio/home, comfort, sound quality, ear shape, hearing loss, brand name, and more, all play a part. The best in-ear monitors are custom fitted to the users ears. You get the picture.
Generally speaking, the best “sounding” headsets/in-ear sets, are wired. Which isn’t to say that some wireless don’t sound better than some wired. It all depends on what is important to you, the choices you make, and your budget. I own what most audiophiles consider to be the best wireless headsets available at this time (without mentioning brands). They sound great. However they do not begin to compare with any of my audiophile wired headsets. The reason is that a straight wire does a perfect job of delivering sound while the lossy combination of a radio transmitter and radio receiver such as Bluetooth cannot. Some will say otherwise, they are wrong, at least for now. If it were true I would already have them. (Please do not confuse WiFi with Bluetooth or RF) (Bluetooth with LDAC is better than no LDAC).
Another thing…don’t buy into the hype. A recent article found the cost of the parts used in a popular “DJ’s” brand was $14, they charged $200. Listen before you purchase. If you like them, and they fit your needs, that’s all that matters. Read on-line reviews skeptically, knowing that what one reviewer likes another reviewer may dislike. Audiophile magazines tend to do a better job and offer more comparisons.
Should Eve get into this field? Do they have any acoustic/audio engineers with a level of expertise to design something as good or better than what is already available? Some companies use stock parts for the drivers and stick their name on them, typically cheap stuff but not always. Designing from the ground up is serious stuff.
Remember this most importantly, my listening needs are unique, and so are yours. Trust your ears.