I usually wear baggy shorts and casual fit jerseys. I'm not fast enough to get much benefit from my snug fitting kit in still conditions. My average on my road bike on a good day and relatively flat roads is 16mph, just barely above the point at which wind resistance does become a factor.

But occasional I do wear the snug fitting kit on swirling gusty days, mostly because it's less exhausting. I've ridden into some headwinds on the open prairie where the wind was literally turning my baggy shorts into parachute brakes. With the snug fitting clothing I'm not fighting the wind so much. But I'm not faster.

All my casual riding buddies who've switched from regular shoes and platforms to clipless say it improved their overall average speed about 1-2 mph. And I can see it in group rides. Folks I used to keep pace with easily now demand more effort on my part. So I may try clipless on my road bike this year. But not on my hybrids.