I don't like it. There's no way to confirm it.
I'm in a progressive league right now where the founder metsmaniac happened to get the number 3 pick (in a league with Kareem Moses and Dr J, seems like you can't go wrong with that pick). I didnt trust it, you can keep refreshing until you get a order that you want. At this point I'm going to avoid any league that uses random.org.
Draftlotto.com sends emails out as confirmation and it's free. I don't understand why the standard on this site is random.org and not that.