"The Voice" Season 4 is heating up as the "Live Rounds" continue again tonight.  

The revamped singing competition has seemed to hit the right formula of judges and fresh spins to over take "American Idol" and all other singing competition shows to become #1. 

The first three seasons of "The Voice" featured judges Adam Levine, Blake Shelton, Christina Aguilera and Ceelo Green. This season, Christina Aguilera and Ceelo Green wanted to take time off to pursue their music and brought in replacements Shakira and Usher. 

Changes judges on the hottest show on TV and when the judges chemistry is such a big part of the show can be risky. However, Shakira and Usher have moved into their new roles nicely and seem to get more comfortable each week. 

Usher is still on top of his game and a huge star in the U.S. but Shakira was more of a wild card.  She has not had many hits in the U.S. in the recent years and is known as being a more international star. 

Shakira has really found her niche' in the show as it has gone on and she has come off as extremely like able to most, while clearing the ratings have done well with her in the judges seat also. 

So the big question is now, should "The Voice" execs bring back Christina Aguilera or give Shakira another season. Aguilera reportedly made $10 million for Season 3 and is asking $17 million for a return in Season 5.  

Aguilera might not have the leverage that she was hoping for though, with ratings higher then ever and Shakira doing so well as a judge. 
What do you think, keep Shakira or bring back Christina?