Curious why you need different drivers for these? How is it different from the stock driver? I thought Mateminco developed a special driver for this emitter that regulates at 32A.
Because the buck driver stepped down at about 90s as it overheats when the light is still chilly cool. I used these type of drivers in the previous GTvn90 before and Turbo runtime was greatly limited by driver heat. Gotta step down when the light is not even warm is not fun and does not fittting for the size of the light. With a light this big its nice to be able to run Turbo for as long as the battery allows. If you are OK with the shorter Turbo runtime of the stock driver you can get Spec A/B which saves a lot of money.
Also some people prefer my driver so they can run any number of cell they want and its the safest battery configuration possible. With just a Single VTC5D you can hit 2.33Mcd! This mean if you only have 1 or two charged cell sitting around you could still enjoy the light at near maximum performance with just less runtime.
Buck, boost or linear all has their place but for the low Vf of the SBT90.2 LED I think linear drivers works out just fine in getting top performance with much improved reliability and and circuitry heat reduction. The added benefits of battery safety and configurations flexibility are all icing to me.
Busniess-wise I much prefer to sell Spec A/B as is pretty much retail asking price, little labor involved and faster profits. Takes me at about 3.5 hours to build a Spec C which mean I can only do a couple a day so its not exactly the Spec I prefer to sell as a businessman.