I've been a little hit-or-miss with the reverse sear method. My last attempt earlier this week was probably the best so far. I'd agree that a thicker piece of meat is more of a determining factor than probably anything else. I lit about 1/2 a chimney of briquettes (plus what I had leftover from a previous cook), and dumped them in the charcoal baskets. I then added a handful of unlit charcoal on top, and closed down the vents to have a grill temp of 275-300. These steaks were slightly over an inch thick, so I didn't use a leave-in thermometer. I just probed periodically until they were 110-115. I pulled the meat and started stoking the coals with a hand-cranked blower; kinda like a bellows pump. Once everything was bright and glowing, I used the "cold grate" searing method and actually used a timer for one minute intervals per side (twice). My wife and I were pretty happy with the results.
In the past year or so, since I started trying to improve my grilling and BBQ skills, everything has been more of a learning/experimenting experience. I may just go back to a sear first way of cooking for steaks less than 1 1/2". Might as well make some comparisons, eh?