The best choice for US buyers
I haven't had the chance to hook these up so this is more a review of the company rather than the product.

I've now placed 3 orders with audiophonics without a single problem. They have the cheapest prices for hypex modules and a bigger variety of odds and ends than any other European website I've found. It's ridiculous that you can't buy this stuff state side but fortunately audiophonics has good prices on products and very reasonable fast shipping rates. My second order arrived in 5 days to the US. The customer service is top notch and they've responded to every email I've sent within 24 hours answering any and every noob question I had. I'll continue to purchase all my diy audio supplies from audiophonics

My reviews of UcD180HG HxR module
https://www.audiosciencereview.com/forum/index.php?threads/hypex-ucd180hg-hxr-amplifier-module-analysis-and-review.27852/

Great product at a great price
The module provides plenty of power and it sounds great: very linear with no audible distortion and, despite the typical class D amp complain, gives many hours of non fatiguing listening experience. I use it in my recording studio to power PMC TB2s speakers and it often happens that I have to listen to music for ten hours a day almost non stop: this amp makes it no harder than any other amp in class AB and reveals details with precision and depth.