As a pentax owner we are limited to the type of strobes we can sue, especially for HSS work. The cactus V6ii allows us to connect with many different strobe brands to give us a greater option of photographic equipment we can use for our work. A great little product. Looking to see what they have in store for the future!
I have used optically triggered off-camera lighting for many years and ran into line-of-sight issues interfering with triggering.
I finally broke down and purchased four of the Cactus V6 II units and I have been very pleased indeed. It only took a short time to become comfortable with the various controls and modes of these units and they are now the only method I use for triggering off camera flash.
Note: If you are interested in HSS (high speed sync), make sure you get the V6 II, not the older V6.