I replaced most of my 50 watt halogen MR-16 bulbs with the 10 watt Philips LED MR-16s last year. They are about $25/each at HD. We use them enough, and electricity rates here in California are high enough, that the bulbs will pay for themselves in a year or so. They are easily as bright as the halogens they replaced. They are also dimmable, but not to the extent that halogens are.

The ones that HD carries have a 3000K color temp. Philips also has other color temps available.

Thanks for putting me onto LEDs, wws! I was thinking that my housings wouldn't take LEDs, but you got me thinking, so I checked it out. Turns out some LEDs work with a magnetic transformer/dimmer. Here are two contenders:

http://www.lalightingstore.com/proled-6-watt-led-mr16-12v-ac-dc-dimmable/
http://www.bulbs.com/espec.aspx?ID=18494&RefId=378

And here is the halogen I like best:

http://1000bulbs.com/product/2513/MR16CG-1225G.html

These all have GU5.3 bases, so I've got a call into Nora Lighting (where I got the housings) to see if these will work in my housings.

So wish me luck! (You've probably guessed that I need it -- I know nothing about lighting...)

Of the two you linked to, the Philips bulbs should be brighter. (445 lumens vs 330 lumens) Color rendering is rated a bit better too. The ProLED ones have a higher efficacy (lumens/watt), but of course both are much better than halogens.

My Philips bulbs are in Halo cans with magnetic transformers, and the dimmers are Lutron DV-600P. It all works fine, though the LEDs don't dim quite as low as the halogens did. I have not tried a LED-specific dimmer with them.

Yes, I heard from Nora Lighting that the LEDs above will work in my magnetic housings! I was leaning toward the ProLED bulbs (way less $$), but have decided on the Philips bulbs for two reasons: 1) wws has tried them and they worked, and 2) the ProLEDs are made in China and have only a 1-year warranty, while the Philips have a 6-year warranty. (Haven't figured out where they're manufactured. Anyone know?)

Thanks for your help, wws!

The Philips is made in China too.

The one I've tried is the AmbientLED version that they sell at Home Depot for $24.97. It is only available there with 3K color temp and is downrated slightly at 435 lumens. (Fine by me as that is the color temp that the halogens are.) The EnduraLED version that you linked to is available from various other outlets in several color temps and output levels.

You might be interested in the link below, where someone tears one apart so you can see the fan. I also posted a short review with links to a couple of photos of the light distribution. In any event, my advice is to try one and see if you like it. Then go from there.

Here is a link that might be useful: Candlepower thread on Philips 10 watt MR-16

Interesting link, wws! And since I'm not an electrical engineer, I liked the pictures you showed. (Worth 1000 words, I hear.) I think the Philips LEDs will be great.

I'd really like to try out one to see if I like it, but is that even possible? I have a series of the housings and no bulbs. Can I turn them on with only one bulb installed without burning out the empty housings? Probably a dumb question, but, again, I'm no EE.

Try superbrightleds.com

Well, I pulled the trigger today and ordered a bunch of Philips 10 watt LED MR16s (item 414771, in case anyone is researching this). I'd already looked at superbrightleds, brushworks, and didn't find a bulb satisfying all my criteria. But thanks for the recommendation! And thanks, wws, for helping me arrive at a decision I'm comfortable with.

I think the Philps are pretty good, but the 7W and 9W Toshiba seem to have greater light output and better color rendition. They also have the GU5.3 base type and are available in 2700K and 3000K.