Never equate Krystal to Taco Hell. Never!!!
Celebrated Chef David Chang wrote in his Momofuku book that I own that Krystal and White Castle are basically the American equivalent of the Asian steamed buns and he absolutely loves them just like I do. A cheese krystal with just the diced onions, pickle and mustard (no added ketchup, relish or mayo) and the steamed bun is just absolute little perfection. And the corn pups and spicy chicks aren't bad at all either.
To compare a little steamed Krystal slider to a five star wagyu hamburger is impossible, they are different entities entirely. (Although I will say that the Cozy Inn in Kansas does ever so slightly beat Krystal and White Castle at their own game and if you're driving through Kansas it is well worth the stop).
Meanwhile Taco Hell is such bad TexMex they can't even call it that in Mexico without offending anyone. Literally the only decent thing at TacoHell is the Baja Blast Mountain Dew which is the best MD flavor imo.