I'm using the Advanced Diamond Drill and I've recently updated the new XyCraft (and Gravisuite) with the glass viewers. The 'vanilla' diamond drill mines them just fine with a decent speed, however the ADD doesn't. It takes probably double the amount over the regular drill. An iron pickaxe is faster. I've also tried regular glass, and the ADD works quickly there. Posted over there and they said it would be something on the Gravisuite side, although I'm not sure. Just a heads up. Thanks.