I got my immersion circulator this week. I've been watching videos and reading everything I can find. What I don't get is the huge window on cook times. Let's say I want to cook a 1.5 to 2 inch thick ribeye or filet to medium. I would set my temp 135-144, but the time says 1-4 hours. Why such a broad range? What is optimal for a 1.5 to 2 inch thick ribeye or filet? Also, for sear I plan to use a hot charcoal fire 1-2 minutes a side. I see a lot of people complaining about problems getting a good sear. Is this a concern?