In the context of what I was saying, challenge maps are a copout from adding new content; i.e. branching story or different perspective ala Half-Life Opposing Force/Blueshift. Honestly don't care how common they are it's just a quicker release. It's more of a moneyplay for people who just buy dlc site unseen. There are people who just want to mash buttons and there are people who want to be entertained and/or learn something along the way.