The light is similar to daylight, so a little colder than incandescent or "hot" energy saving bulbs, the bulbs are a little brighter than 20W lamps. The light is there immediately and glimmers not night with me. Whether the promised 20,000 hours service life can be achieved remains to be seen.
For fast movements you realize that these bulbs very easy "flicker" - the effect is a bit like old tube televisions, but less noticeable.