I absolutely recommend staying at Caglar's place. It is located in the popular area of Istanbul nearby metro, pubs, restaurants, and souvenir shops. The interior is nice and cozy, and the building has a nice common terrace to hang out on sunny days.
Caglar is the nicest host we ever had :) He will recommend you best places and ways to have a great time in Istanbul.
If you want to have an awesome vacation in Istanbul this is the right place for you.
PS. The internet is quite quick(50 Mbps) if you want to work remote