I found this info on Excel energy site:
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Basics
LED technology continues to develop rapidly as a general light source.
As more LED products and light fixtures are introduced on the market, what do retailers, energy efficiency advocates, and consumers need to know to make informed buying decisions?
Building Technologies Program
LED Basics
Diamond Dragon LED. Photo Credit: Osram Opto Semiconductor.
Photo credit: Philips Lumileds
Are LEDs ready for general lighting?
The number of white light LED products available on the market continues to grow, including portable desk/task lights, under-cabinet lights, recessed downlights, retail display lights, and outdoor fixtures for street, parking lot, path, and other area lighting. Some of these products perform very well, but the quality and energy efficiency of
LED products still varies widely, for several reasons:
1. LED technology continues to change and evolve very quickly.
New generations of LED devices become available approximately
every 4 to 6 months.
2. Lighting fixture manufacturers face a learning curve in applying LEDs.
Because they are sensitive to thermal and electrical conditions, LEDs
must be carefully integrated into lighting fixtures. Few lighting fixture manufacturers are equipped to do this well today.
3. Important differences in LED technology compared to other light
sources have created a gap in the industry standards and test procedures
that underpin all product comparisons and ratings. New standards, test procedures, and ENERGY STAR criteria are coming soon. In the
meantime, product comparison is a fairly laborious, one-at-a-time task.
Are LEDs energy-efficient?
The best white LED products can meet or exceed the efficiency of compact
fluorescent lamps (CFLs). However, many white LEDs currently available in
consumer products are only marginally more efficient than incandescent lamps.
The best warm white LEDs available today can produce about 45-50 lumens per watt (lm/W). In comparison, incandescent lamps typically produce 12-15 lm/W; CFLs produce at least 50 lm/W. Performance of white LEDs continues to improve rapidly.
However, LED device efficacy doesn’t tell the whole story. Good LED system and
luminaire design is imperative to energy-efficient LED lighting fixtures. For example, a new LED recessed downlight combines multicolored high efficiency LEDs, excellent thermal management, and sophisticated optical design to produce more than 700 lumens using only 12 watts, for a luminaire efficacy of 60 lm/W. Conversely, poorly-designed luminaires using even the best LEDs may be no more efficient than incandescent lighting.
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I saw a site that sells bulbs to replace traditional bulb but they are $50 a piece!!!

http://www.earthled.com/evolux-led-light-bulb.html

Has anyone tried these for general lighting/task lighting and it worked? What type of replacement bulb did you buy?

Different LEDs have different qualities though. I don't know how good the Excel ones are. And if it's just a screw in bulb, I would question how good it is. The Cree bulb is the one exception I've seen, but it's also very pricey.

But for recessed light applications, we've been extremely successful using LED light sources. They are brighter, more flexible, have better color rendering and sometimes even less expensive than equivalent fluorescent bulbs.

I was thinking of just buying one bulb for a lamp that is used often, the most in my house. If it doesn't work so well I can probably find another place for it, maybe the outside entry light that is really high up and difficult to get to even with a tall ladder and burns out at the worst time, usually when -30 in the dead of winter.