The photos don't do it justice -- the Taksim Mosque is literally right outside the bedroom window and an absolutely gorgeous backdrop to your time in İstanbul. The location is top-notch, a 3-minute walk from the Taksim Metro station, or an easy 13-minute downhill walk to the M1 line into Sultanahmet. Taksim is very lively, especially on weekends, but the windows sealed well and I even slept through the morning prayer call a couple times. The apartment had everything I needed to reheat food, and make tea, and refrigerate leftovers.
A couple of notes: the apartment is on the 3rd floor, but the staircase is wider than most and pretty easily navigable. The bathroom, while well-stocked, is very snug; if you're larger than average size you'll have difficulty standing between the sink and the shower. Also, if you're traveling with kiddos be EXTREMELY careful with them in the shower as it is incredibly slick when wet.
That said, I loved staying here, and I highly recommend it!