Oh, I'm sure its doable, ISTFlyer would be the go-to guy to ask. For me though, I'd be a nervous Rex worrying about traffic, evisa, making sure I got back in time, etc. I'd much rather just have a quick meal in the lounge and chill at the Yotel.

I've got the same time frame as you, next week, arriving IST around 5pm and a 745am flight to BER the next morning.

I just don't think I'd properly be able to enjoy the area with only 14ish hours between flights.