Well mines used to be both.She was on a level not may could reach.I personally thought her live performances were better.She always sounded exactly like the studio if not better,but it recent years her live performances have been a bit inconsistent.
Though she has a pretty solid excuse,but still....
I'd personally still say both,It just takes a lot more effort and vocal rest.
When fully rested she vocally ***** on just about EVERYBODY in the game.
Katy has a lot of bad performances, but at her tour, seriously, she sings so well live. If you watch Katy Perry: Part of Me you can see that. She is a studio singer but she does not deserve the hate she gets for her live singing voice. There are many receipts of great live performances she has.
Nicki is the same way. She raps amazing live, just as well as the studio but it's often more enjoyable live because of the energy she has. Her live singing is definitely hit or miss in live performances, sometimes it's shaky because of how much she's moving on the stage, but sometime it's great.