I’d like to point out another thing: there has been a vote whether the games should contain 5-5 picks and 10 random, or 20 random maps.
I had an argument that the majority of the maps is not difficult. Thus, random maps are favouring teams that are aiming for the mentioned set of maps. It is a fact.
I highly suggest to go the other way: it is much more comfortable for both teams to at least play some of the maps they prefer. Not to mention that it balances the chances, too. I think it is enough to spice things up with 10 random maps.