MN3, old news...that block is fine and all but 12:1 is overkill for 99% of situations (F18, F16, A-Cat). I'm waiting for Harkens response on a 10:1 version that isn't quite as ridiculous in terms of design or cost. They do exist (at least in quad blocks):

http://www.a-cat.org/sites/default/files/21273045_1179570335520824_6052927766471628647_o.jpg


Scorpion F18