My family & I love Naples - it's a timeless, technicolor dream. We spent 9 nights in Marta & Ermin's apartment, and while we didn't meet in-person, they were warm & welcoming. Their contemporary two-bed/bath, Spanish Quarter apartment is very central (we were able to walk everywhere), and located around the corner from one our favorite restaurants - Osteria Don Maccerone.
One thing to be aware of - the non-A/C apartment was very hot. Naples was sunny, warm & sea breezy, but the apartment was an oven, and the three fans didn't really help. I'm sure Cocoon of Naples is a great spot during the cooler months, but if booking during the summer, get ready to sweat.