I saw this listed in the advertised specs for these two cards too, and I wondered what they meant by it. My guess is that they are comparing using the card to the old version of Flashme, before Flashme used the DSL firmware (so you couldn't change the brightness). Of course now Flashme has been updated you can change the DSL brightness, but I'm guessing they haven't updated the MK4 advertising yet. If anyone knows any different, please post.
The site where i bought the key asked neo team about it. They said that you can adjust your NDS brightness after you boot up MK4-key on DS mode. But neo team didn't explain what button to adjust the brightness right after you boot up the mk-4 key ;;;
