Location:
The location is perfect, walking distance to Taksim square and other public transportation such as Osmanbey metro (900m), Taksim metro (1km), bus (400-500m). Havaist bus to the apartment is less than 600m too.
Shops:
There are some tekel and gida (small stores) in front of the apartment, other famous chain stores Sok, Migros, Gratis and even Carefour SA too.
Facilities:
The minus is just the staircase, a typical Turkish old building. You have to bring your luggage up to the 3rd floor but Suleyman bey (the housekeeper) is ready to help. On my last day he even helped me to stroll my baggage from apartment to Havaist. You can cook (some pans, utensils), wash your clothes (Bosch machine). You'll also get stocks of soap and shampoo, spare towels, extra linen too.
Overall, I recommend this accommodation. I'd love to stay there again once I have the chance.