Pros: Uses much less energy than the 40w incancescent it replaced.
Cons: Takes some time to get up to full brightness.
Own the n:vision branded version of this TCP bulb. This bulb is eventually bright enough, and certainly saves energy... It takes some time to get up to brightness - quite dim at first - but fine after about 30 seconds or so. If in a place where it just needs to be on - would be great. If a place with more frequent on-off cycles, might be annoying.