I am extremely familiar with both this building in particular and the area in general, having handled numerous sales and rentals in the neighborhood.
This is a new construction building at the corner of St. Johns Place and Classon Avenue in Crown Heights, one block east of Prospect Heights and one block west of Franklin Avenue, a rapidly-developing commercial stretch including several notable restaurants, like Barboncino and Chavela's, as well as shops and cafes. However, when apartments here were first offered for sale in 2008 this commercial development had just begun and the real estate market was depressed, so they were rented out instead. Units were re-introduced to the market this past June; three are reported to be in contract.
Unit 5C is currently rented out through March 31, 2013, at $2450/mo., which I would say is a good return, given the apartment's size and location. Apartment 2A, a 2 bedroom, 1 bath unit is currently available for rent at $2600; it has been on the market since September, originally asking $2700. Of course, it does not have the outdoor space associated with unit 5C, but it does have two true bedrooms.
Do not hesitate to contact me if you would like further information about this or any other Brooklyn property.