I used my road bike more than my dedicated commuter this summer. At least with summer temps, my change of clothes is small enough to all fit in my Carradice which is easy enough to put on my carbon wünderbike. Don't really need lights in the summer, though lately I've had a front and rear attached. There's just something about riding a lightweight bike with only the bare minimum of stuff inside of it to ride on those 95+ degree days. Harder to do in winter, as clothes take up a lot more space than shorts and a tshirt. I have clipless pedals on most of my bikes.