I don't get it. CF was pretty average for the 2-3 times I've had it over the last few years. I tried IO a few weeks ago at the one by LAX (thank you, Parking Spot shuttle!) and was decidedly underwhelmed given all the hype IO gets. It was better than McD's, but not by much & that's not exactly a hard thing to be. The burger was ok, but in no way anything special. The fries were over cooked and hadn't been properly parboiled first, so they had too much starch in them which left them tasting very cardboard-y.

IMO, in the US Sonic is far better, and Steak n Shake would give both IO and CF a better run for their money. Mos Burger is definitely much better. Most any owner/operator burger place in NZ, Oz, the Cook's, etc will be better by far - although that's probably cultural taste kicking in there.