XVive U4 Monitor Wireless System

So we actually bought 3 of these sets for our church. They seemed to be a cheaper alternative to the regular wireless in-ear systems. The first one came with a defect from the factory on the connector. We returned it and received another one that worked well.
For the first few months they worked well but then one of the senders started to randomly select the channel by itself and although the channels were very rarely changed, the button to change the channel stopped working. You could not press it anymore. We returned it and it was fixed. A month later the 3rd set starting to show the same behavior with the channel button. It is very frustrating to not be able to rely on them. As a summary:
Pros:
- Great concept, works on 2.4 GHz so no interference from other microphones
- Good price

Cons:
- Button to switch the channel is very badly built
- Only mono, which makes creating a good in-ear mix very difficult.

A large sticker on the front of the X-Vive states you can register with them for a 4 year warranty extension. I did so, but there's 2 stickers on the box. I used an incorrect S/N label which appears to be Thomann's own, and XVive's website stated that they had received the registration. I thought, all good, I'll bin the box. Then a few days later I got a rejection email.

It's taken me until now, 3 months from original purchase to find the box. I went to register again with the second serial number and Xvive rejected it because it's out of the 45 day period. I explained the circumstances, and received a cold rejection - no token of goodwill, no exception made for a genuine customer.

I won't be buying an Xvive product again. And our Drummer's U4 pack had a switch failure and had to be returned. Shocking company, shocking quality. Avoid.

It looks pretty sturdy and, but I had to send it back 4 times.
The first problem was the XLR/Instrument connector. The "Click" part wasn't clicking in, so the sound came out way too low.
BTW, you need some strength to attach the adapter to the transmitter.

When I got a new one, it worked for a while but the lows were having a hissed/noise sound. Sent it back. I got the same one back because they couldn't find the issue.

This last one gets interferences (due to the 2.4GHz) that I can't use a wireless system on my Bass anymore.
If you play in tiny bars or are annoyed by cables, that can be the one to go, but not for big stages.

Very good system, and the sound is excellent. As with any system like these, you need good headphones to get the full value.

We use 4 of these, and there is no problem. However, we did have to re scan all our wireless guitar systems.

My only complaint is unlike conventional systems, you cant change batteries. So if mid gig the battery goes, you will have to recharge the system.

Also, would be useful if the system switched itself off if not used for a certain amount of time (I keep forgetting to turn it off....)

The transmitter is also a little bulky. If you are using the Soundcraft UI mixer type, they will not fit side by side....you have to use XLR from mixer, and then plug in the transmitter. (Luckily there are 8 monitor feeds on the UI24, so we just skip every 2nd input)

Overall, its a good system...8/10