Cook may push 60 in control and should get at least to 55+. I also think his splits should reach 80, and 4 70+pitches is attainable.
If he could be a workhorse, I'd be fine with him as a mid-rotation guy (#3). Unfortunately, his Dur/Sta are a bit light, and without top control he's going to burn up his PC faster. With that, he's more of a back of the rotation guy, and will make a very solid ML swingman.