They might look like friends, but they are competing for the playback market. While there is no definite no 1 & both have their own sea of fans. Somewhere they have been made into the asha lata of this era, with sunidhi taking on asha's part with most of the more western & sensual numbers.
Poonam Pandey is the classic example of how the media has degraded itself. If it looks like shit, smells like shit, it is shit. Poonam Pandey looks like the typical C-grader girl who comes to Bollywood with dreams of being a Kareena Kapoor & ends up on the sleaze. However Poonam got lucky with the media picking her shit up, from her stupid quotes to making news of her tweets.