I purchased XVive U4 transmitter for three main reasons, for it's neat size, comparatively reasonable price and that it is battery run.
It is so contained, a very compact transmitter in comparison to other transmitter units, thus saving space carrying multiple units for racks and power. Yes, it protrudes from the output source (desk/rack unit), I've no reason to have an issue with this, aesthetically or practically as of yet.
What may be saved in the cost, could be weighed up against the quality of higher end products regarding signal reliability. For me, at the moment it is a good value product.
The XVive U4 transmitter can be received by multiple units. There are six channel options and XVive recommend use of up to six individual transmitters. These are within in the usual 2.4GHz band range. I plan to be mindful of these channels while also using other wireless devices on stage. There is appropriate apprehension regarding unknown concerns with wireless at every new venue. While using, I have clear sound signal.
The ABS, metal housing material feels well made and sturdy. It is very intuitive to use. Overall, so far, I'm happy with this product, Euphoric.