Hi MW,
I grew up in SoCal, too. In & Out serves a good burger - it's clean, fast, fresh & I like the open kitchen.
Haven't tried a 5 Guys on the West Coast, but a couple months ago, we visited one in the Tri-State. The open kitchen layout is similar to In & Out, and they also use peanut oil for the fries - but, the burgers are **really** good. You get to choose your toppings, too.