Katy lacks the talent and intrigue to last. Recently she's come across as tacky and immature and despite her commercial success in the US she remains highly dependent on her physical attractiveness and team of producers and writers for success.
Gaga. Her talent alone will keep her very much trucking along with her career, even if she has poorer performing albums commercially for the next couple of years. As a musician, in terms of vocal abilities, vision, performing, instrument playing, etc Katy is nowhere near Gaga's level.
