I'm curious how you like these bulbs after having had them for almost two months now. I unfortunately bought 6 BA15D lamps years ago. I had no idea how uncommon the bulbs were, or how expensive.
We have four fixtures, with three lamps in each. One in each of two smaller bathrooms, and two in our master bath. They are really neat looking, modernist, fixtures. And they do produce beautiful light with the xenon bulbs.
LEDs would be nice to have, but the current xelogen bulbs are rate about 750 lumens.
I was worried about the lumen rating situation too. That is why I used the Light Meter app in my cell phone to try and quantify any differences.
Alternatively, I see there are many types of adapters available so you can use different bulb types in a BA15D fixture, so maybe I'll look into that as well.
I thought about this approach, and also some homebrew approaches. But the ebay BA15D lamps showed up and I decided to give them a try.
So far I am reasonably happy with the LED versions. They aren't perfect. For example, the light source is offset a bit from where light would be emitted in the xenon bulb. The spacing between the lamps therefore is a little wierd when you really look at it. But the fixtures we have didn't position the bulbs evenly even with the xenon bulbs. So it is a case of a little wierd becoming a little wierder.
Light color-wise, I ordered the "warm white" version (advertised 3000-3500K), as opposed to the "white" (6000-6500K) version. Even then, they are still just a tad cooler than the xenon bulbs.
Brightness-wise, I published the results from the Light Meter app on my Android phone. Have not seen any degradation in two months. (Just tested again this morning on one of the fixtures that is probably used an hour a day.) It suprised me that the lux level that Light Meter reported was higher with the LED version than the xenon version. I am thinking the color spectrum is different and is 'tickling' the light sensor in the phone differently. As noted above, Light Meter also seems sensitive to some pulsing due, no doubt, to limitations in the built-in power supply. (I see the same thing with the Philips LED GU10s that I have in another room.)
My advise is to order one or two to try out. They are only $6 each. (The xenon bulbs were costing me $10/each at the local lamp shop...) If you like them, the same ebay vendor offers a discount for quantities in multiples of 10. Here is their current ad:
http://www.ebay.com/itm/1x-BA15D-110-120V-Warm-White-lamp-30-5050-SMD-LED-bulb-light-With-cover-BA30B-1-/170908531263?pt=Lamps_US&hash=item27caf13a3f
If you do decide to try one, please report back. It is always fun to compare impressions!