Probably the most common misconception in bbq. Meat will take in smoke flavor for the entire length of the cook, or till it is wrapped in foil. The reaction that forms the smoke ring stops happening when surface of meat reaches ~140 F. So depending on temp of meat when put on and cooking temp, that could vary quite a bit time wise.
I try to regulate smoke, and overall flavor by making sure I have a clean fire burning. That means light blue to invisible smoke coming out the exhaust. Many people make the mistake of thinking that since they can't see smoke billowing out exhaust that it's time to add more wood. Not true. You can hover palm of hand over exhaust for a moment, then smell hand. You will know that it's still rockin'.
Modded Brinkmann Gourmet. Basic UDS. Rescued 22.5" OTS. SJS Mini-WSM. Stubbs. B&B Oak Lump.
Cannondale 2009 F8 (for burning off all the great BBQ)