I have yet to play with it - Been busy and it's for my significant other, so I may not even be allowed to play with it...
But. I did call Jim at ISC. Apparently they did this to help the people who can't see yellow (a 1.0). So - there will be one LED that is the normal (well now new since it it staight red under .4) ISC pattern, one green LED for 1.1 and above, and both will light for a 1.0.
Once again that is my understanding - basically all it does is avoid the yellow at a 1.0.