I didn't find clipless pedals to increase my speed particularly, but I have gotten quite used to them at this point. (Less-knobby tires and a pump with a pressure gauge were each good for 2-3 mph.) But I don't have any sort of bike-mounted bag right now, which does limit the amount I can carry around. I've mostly been doing "long day trips" over "commute by bike" so far and so the amount of things (lock, water, spare tube, small tools) I can carry on my back has been good enough.