Please do, I'd really like to know.
FlexRaid costs about the same as unRaid does, give or take a few dollars. In fact, if you want to use unRaid with more than 6 drives, it costs twice of what FlexRaid costs (and FlexRaid is not limited when it comes to number of drives). The cost is not a factor for me, because I was (and am) willing to pay for unRaid as well.