Went on the weekend. A beet greens and ricotta salata sandwich was truly delicious. The cheeses look vastly better aged than anywhere else in Park Slope and there is a prominent aging room. But the location is even less salubrious than franny's and, judging from a couple of direct comparisons, the prices seem to be slightly more expensive than at Blue Apron or Union Market, the local competition. (And even if the Park Slope Food Coop is not a fair comparison, members still can buy quite a lot of the same dry goods at a fraction of the cost -- Bklyn Larder should have tried to set itself apart more.)
Maybe the focus will eventually turn to more pre-prepared food, like $35/lb octopus salad.
My girlfriend and I think Brooklyn larder might well fail where franny's has succeeded: we love franny's, but the bill for two people can easily top $100 when you only have a salad starter, a side, a pizza, a pasta and the cheapest bottle of wine. The success of franny's clearly demonstrates that people are willing to pay steeply to eat class (if simply-prepared) ingredients at a restaurant on Flatbush -- perhaps especially when they live nearby. But a deli is not a restaurant. In this economy, Brooklyn Larder might have a tough time.