With almost any flashlight/headlamp there will be a difference between the specifications they are marketed with, and the specifications you get from the Performance Check. This is the case because almost all flashlights/headlamps will have to dim down the light in some degree.
This is mainly due to one factor: heat build-up.
When running an LED there will always be some degree of heat build-up, but too much heat will damage the LED. You will always want to get as many lumen from the LED as possible, but the more lumen the more heat, and at some point the light will have to be dimmed down in order to spare the LED. This is not the same as programming the light to perform well in the ANSI FL-1 test, but is necessary in order to get the highest performing product without harming the LED.
At Suprabeam we aim to give the user maximum control over lumen output and runtime. This is done by having a MAX level where the light runs on the highest possible light level.
When running the LED this hard, the light will have to be dimmed down at some point to prevent damaging the product. This is why you will also experience that most Suprabeam models dim down the light level. If you wish to prolong the runtime or avoid the dimming, you can use a lower light level or use the dimming function.
This way you are in complete control of the lumen output and battery life.
You should expect the average lumen value from the Performance Check to be lower, but if it says 600 lumen on the box and the average lumen is 115 you should not be satisfied.