I was soft pedaling while coasting the other day, meaning the freehub body was clicking, aka not engaged. I could get the SRM to read 2-5 watts. I know my bearings are pretty crunchy, not as bad as 2010 (when I could get the SRM to read 15 watts on no load - the bearings were literally indexed every so many degrees). My comment on Contador's bearing thing has got me thinking that saving 2-5 watts would be significant for me, at least in terms of background wasted energy. One of these days.