Did you feel a seismic shift at around 11 a.m. today? That’s when Chicago’s first official Shake Shack location (66 E. Ohio St., River North, 312-667-1701) opened to the public, with a line out the door and down the block. Expect this phenomenon to continue for the time being—this place is going to be mobbed. Luckily, the line moved fast, and we got our first taste of what people in New York (and D.C., and Philadelphia, and Dubai….) have been freaking out about for years.

We’re withholding judgment on the Shack’s iconic burgers for now—too many to try, not enough mouths. Instead, we tested all three of their Chicago-exclusive concrete flavors (think Dairy Queen Blizzard—a cup of custard with all manner of mix-ins) and ranked our favorites below, from worst to best:

3. Shack Attack

Chocolate custard, fudge sauce, chocolate truffle cookie dough, Vosges black salt caramel chocolate, chocolate sprinkles
There was a pretty wide gulf between this concrete and the other two, though "worst" may be too harsh a term. It’s not like this was some kind of abomination—it’s chocolate custard with a lot of chocolate stuff piled into it. But the whole thing was a little one-note, and we weren’t crazy about the tooth-shatteringly hard chunks of chocolate woven into the mix. This is the one we wouldn’t order again but would definitely sneak bites of from a friend while she wasn’t looking.

2. Da S’mores

Vanilla and chocolate custard with a slice of Bang Bang Pie Shop’s s’mores pie
First, good on the Shake Shack team for joining forces with one of our favorite dessert purveyors, the ever-delightful crew at Bang Bang. Also good on them for picking the fudgy s’mores pie with a killer graham cracker crust. The one problem? You do have to go digging for pie—there were several giant gobs of it rather than an even incorporation. We also would have loved some extra marshmallow and graham cracker action to really drive home the s’mores-iness of it all.

1. Salted Carame‘L’

Vanilla custard, banana, Glazed & Infused salted caramel old fashioned doughnut
We had our doubts. But the genius here is in the selection of a dense, crumbly old fashioned doughnut, which absorbed some of the custard, didn’t freeze, and wound up perfectly, evenly distributed through the cup. Every bite had some doughnut action, and the banana wasn’t cloying. We’ll take a double next time.