Malkoff, BY FAR! Because Mag has retained the cammed focusing system (a relic from their incandescents) in their LED lights, the emitter needs to be able to move. This means it can't be fixed to a proper heatsink, which means the light has to power back to prevent overheating of the emitter. Simply put, with the Pro, you only get those 270 lumens for a short time before brightness has to drop. On the other hand, with the Malkoff, you get full brightness for as long as your batteries can support it. The Malkoff unit does still allow some degree of focusing, but it's not nearly as slick as on the stock Mag. However, I'm gladly willing to pay that price (and the increased price of the light + drop-in) for a good, bright light.