Rated highly- no progress on lats until I installed a pullup bar in my home gym and things started happening.
My current pullup routine
Warmup Set (partials, getting the blood flowing) as many as I can do
Sets 2-5: 8-9 reps X 60lbs, then supersetted with weightless pullups 8-10 reps, then "hanging" for a ten count
This is a "movement" exercize, so complete extension is crucial and don't use body motion to cheat. Nice secondary benefits to the biceps as well.