I don't really want to argue, but... 1) I wasn't talking about reaction wheel torque, I was talking about it might make SAS more responsive. 2) It's not about what they're intended to be used for, it's about what they can be used for. (i.e. Mublin using engines as fairings for his rockets) 3) It's there for the looks, as it allows you to make powerful and good looking 1m engine clusters.