These are generally excellent. They are well constructed from good materials and look like they will last. In use, they are quiet and transparent. The only time I have experienced drop-outs was then the receiver was right beside a Wifi device (a smart plug). Other than that, they are perfect. I haven't tested the limits of their range.
There are a few minor annoyances. There is a 6mm socket which allows the transmitter to be plugged into the receiver for charging. This (cleverly) also doubles as a way for them to agree on a clear frequency to use (you plug them together for a few seconds until a light flashes and they will figure out the best frequency to use). This is also a tempting way to store them when not in use, but if you do so, the batteries will run down. You can't store them plugged in together like that.
Second, there is a small pin near the base of each plug that is pressed down when you plug the units into the guitar (transmitter) an amplifier (receiver). The socket in the guitar/amplifier actuates this pin when turns on the transmitter/receiver. This saves having to switch them on and off with a switch. However, if the "mouth" of the 6mm socket they are being plugged into is a little thin, reliably actuating that pin can be a little bit hit-and-miss. I found one guitar where the socket wall was inclined to "miss" the pin and failed to turn on the transmitter. Would be easily fixed by adjusting the guitar socket.
The complaints are very minor: overall I'm more than satisfied with the quality and performance of these.
