I have 4 of the Zulu3 headsets and the 2 of them that I bought in 2020 and have used less and kept in their cases at home, which apparently was a mistake, have gooey plastic. The problem with the plastic deteriorating is NOT fixed in the Zulu3 line either. I would have followed Lightspeed's advice, had they given any. Removing the soft covering on the control box with rubbing alcohol did work on the other headsets, but my sticky Zulu3s have the problem where the band adjustment is and also on the plastic around the ear cups right next to the part that gets replaced with the refresher kit. Lightspeed knows about this problem but hasn't change their design and doesn't list the issue in theri FAQs. Not all plastics have this problem, and pretty much any materials engineer could fix the design.
Also, the headset I use most sometimes has a banging sound. This problem happened twice before with a different headsets and Lightspeed said the problem was "weak ANR" which isn't exactly root cause; it seems the ANR circuitry just goes out with use.
At this point, I've had four 20XLs, two Zulus, and four Zulu3 headsets. I've been a Lightspeed customer for decades, but the next time I need to buy a headset, I'm going to give one of the other brands a try and hope for better quality. I really can't think of anything worse to say about a company than to say that they drive very long-time customers away, but that's how it is.