I got the XM6 with the 2 transmitters (for 2 people) even though I'm currently only using one. The sound is incredibly good. Whether directly with its built-in microphone or with the lapel extension, I couldn't tell the difference from the sound produced by a condenser microphone when I hold it in front of me. It works perfectly even when I put the transmitter in the pocket of my shirt.
I put the lapel extension through my clothes and it captures my voice perfectly, even when I'm outside and it's windy or raining.
The range is excellent, but the connection can be momentarily interrupted if my body comes between the transmitter and receiver. The receiver has a jack, so it can be connected to all DSLRs and devices, but if the phone doesn't have a jack, you'll need a dongle (shown in the photo). With my Panasonic G95, the improvement is huge compared to its built-in microphone. Especially at a distance, there's no comparison. The battery lasted over 6 hours, much better than any of my useless GoPros.
The OLED screen is a real OLED. It looks completely black whether it's working or turned off. I like that it shows the gain and you can adjust it from both the transmitter and receiver. Also, the connection was very easy. You just turn on the receiver first, then turn on the 2 transmitters, and they sync automatically immediately.
The negative point is that they give you a small bag (photo) instead of a charging case. Okay, they charge with USB-C, but I would have liked a case. There is a case, but it's very expensive, especially compared to the price of the XM6-S2 kit, which is honestly very cheap for what it does. We're talking about professional quality that you find in kits that cost 500+
