I have transited IST several times and every time I transit the security debacle for connecting passengers is atrocious. First, good luck finding the line you need to be in (economy vs business vs *A). The "helper" for the line won't help.

Then, good luck having any concept of orderly security checking. The Turkish (and the people connecting in IST) are pushy to say the least. They won't wait in line. You will have to get pushy right back. They expect it and they appreciate it, I think.

Once you get past that security you will be fine. I've not had additional security screening after that, even for flights to US (e.g. IST-ORD). Maybe I just got lucky.

If you do decide to go to IST the night before, remember that you will pay a $20 e-visa app fee that you need to do before you fly to IST. Or you can pay $30 at the airport for an on-premise visa.

-RM