I spent last weekend cave diving in 20-30 viz waters of the Roubidoux Spring Cave system. I had with me the new Halcyon Focus light and the groups I was diving with had UWLD 15, 26, and a 35. I was able to avoid all the blinding backscatter by dialing in the focus. At the end of the day, everyone agreed the Focus was a game changer and a versatile light for many applications.
I personally ordered the light after having dove a prototype in a cave course. It was more than powerful enough to be seen by a 35W HID diver in the lead position. I was impressed enough by the light I bought two of them for everyday diving and video use as the beam pattern widens to more than enough. It's also nice to focus the beam to the diameter of the passage you're going through. As much as I like the build quality of UWLD, and the customer service of LM, the Focus has no rival. FWIW, demo the Focus and let it speak for itself.