Agree, do not over-trim. I put temp probes in the flat, and also in the point. My goals are 195 in the flat, and 200-205 in the point. Find a balance between those, take it out, double-wrap in foil, and rest in a cooler with towels from 2-6 hours. Going by feel is good once you have some briskets under your belt, and you know what to look for, and feel for. If you do not have those years of experience, go by temp.
24 hours sounds like a pretty long time for your 16 pound brisket, assuming you probably trimmed a scant 2 pounds of fat off of it. Briskets generally take 1 to 1.5 hours per pound at 225 (you mentioned you were cooking at 200, so that would explain the increased time).