Any way to brighten Monome Leds?

I have a Grayscale 64 and a monome kit 256. The Grayscale is SO nice and bright. I can even use it outdoors in full bright sunlight. Is there a way to brighten up the leds on the 256, or is that just a massive job? How is the brightness on the new varibright models?

Maybe I should hunt for a used gs 128?