I just used four CR6s in a couple of new bedrooms - these are older ones back when even the 6" lamps were only 575 lumens), and find them adequately bright. I don't care for CR4s in a bedroom because they give off almost as much light from a much smaller area, so they're *really* bright and glaring if you look up at them, which you will sometimes when lying in bed.

Also be sure to get the "Truewhite" 90 CRI versions (9.5w), not the builder-grade 80 CRI, higher wattage (but no brighter) "builder grade" ones that HD recently started selling at least in the 6" size. Those won't give off good-quality light.