I am going on a vacation to Istanbul and am hesitant as to where to stay?

Sultanahmet - Because it's very close to main touristic attractions, like Agia Sophia, Basilica's Cistern, Blue Mosque, Topkapi Palace, Istanbul Archeological Museum, Hippodrome, Grand Bazaar, Spice Market..etc. but you should definitely see Taksim district as well, especially Istiklal Street & Galata Tower :)

I think Sultanahmet area is very good for you..

in taksim u can go out after midnight and enjoy well but in Sultanahmet u need to get in a taxi to go Taksim after midnight :P

Turkish character.. hmm may be u can check some "konak" hotels in sultanahmet..They are generally boutique hotels but they give good service.. Dont forget to check tripadvisor before booking..

Sultanahmet is a good area to stay in, I liked it. Great eateries around there, and you're not far from the great Mosques and Topkapi Palace. It's easy enough to get to Taksim either by public transport, or if you're feeling energetic, it's a nice walk.

Out of 12 days in Turkey? It relies upon on the season, the place else you intend to circulate to, and your hobbies? in case you will circulate to Turkey in spring, i might advise spending all 12 days in Istanbul. If in summer season and you're into swimming, beaches and you will circulate to those cities too, i might advise 5 days in Istanbul and one week in southern or agean element of Turkey. If in iciness and you will circulate to ski centers etc, 7 days in Istanbul and 5 days in others. in case you probably did no longer ensure the time yet, attempt to do it in spring (while Istanbul is the main eye-catching) or in summer season (while the two Istanbul and a brilliant sort of different areas -beaches, cappadocia, additionally the black sea area- are all ok)