My 25 years old daughter and I spent 3 nights at Leon’s. The area is absolutely charming: cozy, quiet, safe, and main streets are full of shops of all kinds (Enoteca on Court is worth visiting for a little good and affordable Italian dinner!)
The metro station is 5 minutes walk, very convenient to Manhattan (count still several stations).
Our exchanges with Leon were easy and friendly. His friend Lester was there when we arrived (If you come by car, parking is difficult on weekdays, much easier the weekend).
Eclectic, the apartment is just as on the pictures. Everything was clean ... except the tub (an oversight?). The PLUS of the apartment is of course the terrace!!
Our problem: forget the couch to sleep, it is not comfortable at all.
In summary, we enjoyed our stay at Leon, and Carroll Gardens is truly a neighborhood in Brooklyn we recommend!