The Mother. I think I'm up to six. Two in the camper stay loaded with a minimal kit, 2 gyuto, petty, suji (of course) and a parer. Held on with couple small screws and double sided tape. Recently had an accident that totaled the camper. Knives were a bit skewed but still on the racks, racks were still on the wall. (Unlike most of the rest of camper).
Getting knives on/off the block requires some finesse. On - Hold spine facing block, perp to block. Touch spine to block then rotate knife onto the block. Reverse to remove. Off - do it in reverse. This will minimize the pull on the block, good for the block, good for the blade.