From my understanding the controller in the 1600 Pro Series uses a different chip set. It looks and operates the same minus the issues of the 1150. That being said, some are having issues with their 1600. My 1600 so far has been great. My only issue is that it does not like to hold 250°. Every other temperature works great.I looked at the 1600 at Lowe's, it looks like it has the same controller as the 1150, we will soon find out if people are having the same problems.
By the way, I haven't seen the 1150 at the 2 Lowe's I go to lately, I wonder if it was removed.