These are coming along, but really no good for replacing flood lights at all, and so far only good for very low wattage spots. the 5 wattt and triple 3 watt ones put out enough light that they can be actually useful, but are not as bright as the real bulbs. You cannot convert a candle to a lumen that easily so it's not that straightforward, but they are definitely dimmer.
The other problem with these bulbs is that the brightest ones come in very cool white colors. Like 6000k color temperature. Which is fine for the high bay lights in the loading dock, but nobody wants that in a 30 watt reading lamp. Many do also come in warm white colors that are more like the bulbs they are replacing, but you'll have to experiment to see what you like best.
The problem with LED's is that you cannot run them in a setup like this with just a resister ballast. As the LED's heat up their resistance goes down, allowing more current to flow making them hotter and still lowering their resistance. If you're running them close to the edge you can actually get to a runaway condition that ends in their bonding wires melting. So they have to have a current limited power supply inside, and very good heat sinking. As we know from CFL bulbs, cheap power supplies burn out quickly.
There are dimmable ones just reaching something like a sane price point right now, in another year I expect them to be about ready to put in, but right now the good ones are too expensive and the cheap ones are just garbage.
Additionally, since all of the light is focused, they dont look nice in decorative fixtures at all. I have some MR16 bulbs in my front hall shining on some pictures that I'd love to replace with LED's, but the fixtures are frosted glass which glow nicely from the wasted light from a regular bulb, with an LED in there they would just be dark, illuminating only the picture and not the hallway unless I point one there.
