Personally I think Checkers is vile. (I ate there way too much while on an extended stay in florida for a little election problem a few years ago. Could be that little trip that soured me on checkers )

In-n-Out on the other hand is great. I made this the only must do on a mileage run to LA a little over a year ago. (It was a seven hour trip to LA highlighted by In-n-Out). I really do love their food.