I commute weekdays and roadie on the weekend. It's all one of a kind. The way I look at it, if I have a destination while on my roadie, then I consider tha it as a commute. Same goal but different tool for the job.
When I do get on my roadie bike, sometime I turn around to check my rack and pannier. The load and the weight difference gives me a false sense of something is missing or fallen off back my bike.