The Cree BR30 LED puts out a claimed 650 lumens from a power draw of just 9 watts, costing a little over a dollar per year to use. A comparably bright incandescent floodlight consumes 65 watts, and costs almost 8 dollars a year to use.
All LEDs will see a slight dip in brightness after you first turn them on before leveling off. This is due to heat buildup. In the Cree bulb's case, heat affects it a little more than the competition -- that means it might not b e the best choice for an enclosed fixture, where the heat can't escape.