I used one on a recent Big Muff build. It's handy and straightforward. Basically everything (except power) meets at the 3PDT board, and the documentation is helpful.
The board has a place for the LED and its resistor, and you can mount the LED directly on the board if the hole for the resistor is closer than an inch from the hole for the switch body. I used a predrilled enclosure with the holes 1.5" apart and it wouldn't reach, so I just aimed the LED toward the hole to illuminate a plug of hot glue and I'm satisfied.
If you're accustomed to soldering on etched boards, i's a good way to go, IMHO.