ive quit many jobs. 2 week notices are for tools.
why burn those bridges? why screw those companies over?
I'm in the process of switching jobs and of course I'm going to prioritize the newer company, but if I know I'm going to start working at the new place in 2 weeks, why not just say "hey, I've got a new job and I start working in 2 weeks, thanks for the opportunity you gave me."