Hi All,
I too now have a UD1-U on the way. I had just got done mounting a pair of CNC4PC C10s breakout boards, which are very nice for the purpose. But the C10s has no (LED) indicators, and yes is 5v only, but that's okay and easy to work with. I am now pulling those out to make room for the UD1-U.
The UD1 is very compact, has LED indicators, has spring terminals, ground-loop eliminating design, and directly integrates with the UB1... all that and more make it an excellent choice for creating a more reliable system.
For higher current switching needs I've purchased "relay modules" (5, 12, 24v) from Amazon. These are very useful, and also isolated, nearly all have LED indicators. I especially like the SunFounder 5V Relay Shield Module
https://www.amazon.com/gp/product/B00DR9SE4A/ref=oh_aui_detailpage_o07_s00?ie=UTF8&psc=1Thanks CNCroom for your thoughtful designs!