Why do you think this? Maybe you are thinking of a regular C8 with xml2. I compared these 2 lights here.

If we are talking about a C8 with xpl-hi and FET driver, like a Astrolux C8, we have the same emitter and same lumens, but the GT Mini has a slightly larger reflector which gives it a tiny bit more candela and distance. So not a big difference at all.