Unless Whataburger has changed their formula recently, it is by no means the equivalent of In-N-Out. I love and miss Whataburger but it’s definitely char-broiled and a completely different sandwich than an INO.
I also miss Krystal burgers. It’s always dumfounded me that there’s absolutely NOTHING like Krystals on the West Coast. Closest is White Castles from the grocer freezer’s section. Every time I fly back to Mobile, my family knows to stop for dinner at Krystal on the drive from the airport.
Finally a vote for Krystals.
As a vegetarian ( yes I personally revoked my manhood ), I go to Krystals and eat grilled onions smothered on the buns with mustard. Or I take a bag home and add my soybean burger.
Nice thing about Krystals ( real or modified ), you can eat dozens at a time.
I'm pretty sure I've been to the Airport Blvd Krystal a time or two. I don't really remember, though.