I'm just dipping my toe in the water at this point and ordered the bulb at the 2nd link I posted earlier, $24 shipped. I don't plan to order ME's whole headlight but if someone else does I hope they post their observations here.

Don, it has been nice bouncing back and forth with you.   The bottom line is any LED drop in is brighter or whiter and more visible in the daylight than the stock incandescent bulb.

One of the first LED units I dropped in was roughly $30.  If I were 100% certain I would not get caught out riding at night, it would still be in the bike and I wouldn't have three or four more in the tool box taking up space LOL.  Nor would I have the LED in the bikes I have now.  St.

► These standard "sealed beam" LED headlamps ( http://motoelekt.com/lighting.htm ) have been around for about 7 years. Their strong point seems to be that they have multiple light sources, placed at varying positions around the reflector to give a better, true "motorcycle light pattern".

► As the Motorrad Elektrik web site states, it's the standard 7" all-in-one (light source & reflector) product with a rim added so that it will correctly fit the larger 190mm (7.48 inch) BMW headlamp bucket. 

► The base 7" product seems to be from a company called Sunpie, which is available on Amazon for $40 to $60. (Amazon Link) Then it looks like someone designed an adapter, which is probably 3D printed, allowing the 7" sealed beam to securely fit the 190mm Airhead headlamp bucket. That's a very ingenious solution !

While looking at the Amazon page, if you'll click on the last item photo it will play a short movie that shows the rear of the sealed beam. The movie reveals that the electrical connections are made via a short wiring "pigtail" that protrudes off-center from the 7 o'clock position on the rear. The pigtail ends in a standard 3-pin headlamp connector, so electrically it's a 100% "plug & play" connection. And, due to the off-center wiring placement and apparently shallow reflector design, there will be very, very little interference with the Airhead's wiring inside the headlamp bucket.

► Light output is 3500 Lumens, making it brighter than the H4 LED bulb, but I could not find any details on power consumption.

Great find !

Additional info from Motorrad Elektrik re the sealed beam LED headlight.

"They appear to consume 40 watts to run the drivers, no difference in hi/low.

The black option refers to the “reflector” as seen from the front, no difference in the light itself. Looks great with a black bike.

Yep, the light is sealed per DOT mandate, replacement is the only fix."

Removed the OEM "front beam guard prong" from my '84 RS and put in a plug'n'play Novsight M500-N36US-H4 LED bulb sent to me by an acquaintance who has been installing these in customer's bikes for several years (bulb now apparently discontinued because I can't find it online even at the manufacturers website). Kinda odd looking - has its own "front beam guard" thingy, looks like 3 round ridges.

?

During daylight in my garage at my 15' headlight aim points on the wall (per owner manual) I could see the dim beam cutoff line going left at 9:00 and going right at 3:00 angling up toward 2:00, reminiscent of the halogen bulb I removed. Check.

Bright beam almost washed out the upper aim point with lotsa light striking the wall around and above that point. Check.

So far so good. If I find myself riding at night it'll be due to poor planning or bad luck, but I'll pay attention to road & ditch visibility and if oncoming drivers are indicating they're being dazzled.

Don, thanks for the update.

As for all this, beam pattern is mostly due to light controlled (sorry not a good word) by the glass lens of the headlight housing.  The more even the light projected outward by the reflector the better the beam pattern.  

Yeah, I have got a close but no cigar LED bulb in my headlight without removing the center "guard Prong" but it is still not as good as original halogen bulb pattern. 

Just for laughs, there is a difference in the headlight lenses for UK and Euro, US.  The UK projects the high side or curb side beam on the left instead of the right.    

Sadly, a lot of people stick LED bulbs into headlights without a thought about beam pattern and piss off oncoming drivers at night or find out they can't see the edges of the road only a blob of light in front.

Thankfully you are one of the smart guys who take a few minutes to do what is right.  St.