Those twins, wow, amazing. If you read something like that from a fictional story, you'd think it sounds far fetched, but this is real.
They could be in an unique position to prove or disprove the many philosophical statements made about qualia, which is thought to be definitively subjective to the person and inaccessible. Not anymore, it seems.
Not sure if that solves the qualia debate, but it definetley opens new considerations for self-hood.