my most daunting block to date (not quite finished with mine yet) was definately D-11 i did that one for the blue/white/gold block that klue did and wound up throwing it across the room. when i told my Mom that i had thrown it she said "wow that is not like you." she has watched me rip out seam after seam on something i was making and not even break a sweat. D-11 actually made me cry. my advice on this one is to see if you can rework it to make it easier for you.