Sunidhi in her element! And Vishal-Shekhar know how to extract the best from her.
This song has the complete Sunidhi: her soft voice, her throw and her versatility. She's just as comfortable singing words like 'Saiyan Saiyan Saiyan, chhodo more baiyaan' as she is with 'Boy you got me feeling, feeling like I'm dreaming'.
I don't think the song was very difficult. It incorporates a small range in pitch and there is nothing too sophisticated in Sunidhi's projection: it's just throw on 'Mahiya' and less throw on everything else. Also her voice breaks a bit in 'Saiyan Saiyan Saiyan.... Mori Baiyan'. Of course, she gets points for feel and voice control and throw.
Unfortunately, Sunidhi's singing didn't have the soul required to cross teh threshold between 8 and 9 for me.
8/10