I currently have 2 of these, plus 2 extra XSW IEM EK belt pack receivers to put a 5-piece metal band on in-ears (1 is hard-wired). We're using it in combination with a Behringer X32 rack, and have been greatly enjoying the upgrade when compared to the floor wedges we were using before.
We make heavy use of the "focus" mode on the receiver. Allowing us to have 4 individual mono mixes that the artist themselves change. No more "hey, can I hear a bit more of x?", just turn it up/down yourself.
Although the belt pack does feel as if it's made from plastic, it has met the floor a few times already, and hasn't shown signs of breaking yet. So, I'm fairly confident that they'll last me a while.
Overall, a great product. It does what I need it to do right now, and it's giving me upgrade paths for future builds.