A firmware upgrade like that would only work on v.5 firmware and up of the original DS, the others don't have the power management setup for it. And even if it did, the battery life has been known to be far lower than normal, the brightness will only go up to 3 since brightness 1 turns off the backlight, and the color saturation will still be no better than the original GBA/GBASP mk1. I'd say the only issue I'm having is playing Metroid Prime Hunters with it, if you've played it with the pinky underneath the system all this time the stylus and form factor make it feel completely different.