Jack, your diagram is for a “Quick Stop” method? (at least that is what we call it). For beam reaching and above, this is our preferred method. As you know, the boat needs to travel a little bit to get the Lifesling to trail out behind (those of you who think they can throw it out to the MOB, really need to practice with it.) The Quickstop does this and pulls the Lifesling in an arc to better capture the MOB. If you miss the MOB on the first pass, the Lifesling will "lasso" him. Downwind running with a spinnaker is an altogether different animal. In this case, we do a Figure 8 retrieval as we need to get the kite down first before we can go head to wind (though, we have done the maneuver utilizing a “Mexican” take down before). It is pretty scary to be the helmsman with the boat traveling away from the MOB at a high rate of speed while your crew are preparing for a short-handed take down.
It doesn’t matter if you are sailing or motoring – big seas are big seas and you do need to time your fall-off to downwind so you are not beam to the wave face. You do want to be proficient in your helming skills. Doing practice racing starts (and pre-starts) is a good way of gaining confidence in one’s boat handling skills under sail power. From the “what it’s worth department” all of our MOB practice is done under sail and over the past five years I have a perfect score – I will pick you up on the first pass every time.