This is my 'n' test to include vraylight material in a standard light setup as arealights to decrease the render time.Sometimes ago I wrote a short tutorial (you can find it at: http://www.treddi.com/forum/index.php?showtopic=15315
where I shared the results of my personal testing in vraylightmtl solution.
this image needed less then one hour to render at res 1400*1050. just because include 2 vraylights and 2 planes with vraylightmtl.