Im using "quantum board" - cheaper china copy but same diodes or close to anyway.. yes they grow very good.. i have 4 boards for my 4x4 running at 130w each board.. i would maybe add a bit more to really cover the full area for next grow.. under those LED I think cal/mag issue is one of the most common.. for one reason or another seems like those light have the plant use more of those nutrients (i got no scientific proof just lots of reading and personal experience).. for the rest its test and learn in terms of distance but in flower it should be in the 18-22inches from the plant..
Last thing that I would add is using those high efficient LED create less heat than other type of light which is good to control room temp but also affect leaves activity.. so you will want your grow room a bit hotter than you would do with HPS for example.. i had read a nice articles with leaves temps with different type of light and at the same room temp leaves temp under hps were higher of a few degrees to leave temp of LED so to compensate youd want a bit warmer room temp (probably in the 25-28celcius range when light on)
Im still learning but you can check my grow journal if youd like to see some WW under those lights
