This may be the tastiest burger I've ever had.
If you're not gonna do the "Six Dollar Burger" version, then just try the Single. There's no need to do the Double, they just double up the beef. The chiabatta roll is a great change, and the "creamy horseradish sauce" adds a real nice spice. Grilled onions - MWAH! The swiss cheese is perfect and, as much as this seems like an imitation of the Jack in the Box Sirloin Burger, the substitution of all the veggies with Prime Rib makes this burger a whole new ball game!
Keep in mind, though, that this is TOTAL JUNK FOOD. It's terrible for you. But in a pinch, (and in my humble opinion,) it's the best bang for your buck.
The next time you're at Carl's Jr., give it a try. And post a comment here about how you liked it. THAT'S AN ORDER!