It's all simply nothing more than marketing double talk. high pressure sodium and Metal halide are both spark gap technologies. These hod's are nothing more than tungsten filaments in inert gas...the exact definition of a halogen lamp. Nothing new to see here.

 

Yes I did more reading and stand corrected. But apparently their are some other factors that can effect brightness.
(quote from a toyota forum)

"It was GE's goal to create a bulb that produced 75% of the light output of HID headlights at 25% of the cost. GE sells HIR bulbs for residential lighting and specialized projectors, but decided to stay out of the automotive market and licensed this technology to a division of Toshiba. In fact, Toshiba and GE are among the few companies in the world with the expertise to engineer and build this product. These bulbs attain light levels 75% to 110% brighter than stock as a result of an engineering process that deposits multiple, yet almost invisible, layers of semi-reflective coating on the surface of a specially shaped quartz bulb. This coating ( a titania/silica, zinc oxide/silica, zirconia/silica, silicon nitride/silica, and titania/magnesium fluoride tantalam/silica multi-layer dielectric, according to the patent) reflects a portion of the infrared energy emitted by the filament back onto the filament, causing it to glow brighter and emit more light from the uncoated forward portion of the bulb. Although the filament gets hotter, the glass does not. IT GENERATES NO MORE HEAT THAN A REGULAR HALOGEN BULB, AND IT DRAWS THE SAME WATTAGE AND AMPERAGE AS THE STOCK 9006 BULB IT REPLACES"

I see from actual users of HOD bulbs that they have mixed reviews with one person seeing a huge change and another seeing none... likely just one person having older dim bulbs prior to changing them.

 

Lens design is big business as it speaks to how efficiently the light being generated actually makes it onto the subject to be illuminated. Since the biggest efficiency hit in these spotlight type applications sucha s auto headlights is in the lenses that is a good point of interest to focus your development efforts. Whenever you can more effectively get the light out from things like anti reflective coatings you get the bonus of less heat build up in the lens and since things will be cooler the potential for running more power safely.

 

Thanks fellas i think I will pass on them and stick with the silver star ultras.