I like Nadine in the setting of GA, but I have always thought she was overrated as a singer, she actually sounded pretty weak with little power in that performance, Love Machine and The Promise were bad imo. Maybe she was sick or something.
Putting tone and personal preferences aside, Nadine is clearly the most talented vocalist of GA with the best vocal range and technical ability. She is also the best all round performer, she gives so much energy and attitude on stage, Cheryl does too, but Nadine has the edge. It's a shame her music career is destined to amount to nothing outside the group. Her album was amazing, it showed how versatile she is and demonstrated her songwriting skills..
I don't feel like Nadine necessarily sings lead on most of the songs. I think there's actually a pretty even distribution amongst the girls. Definitely not like Nicole and PCD.