"Have either of you ever done a real life rescue?"
Not a full blown MOB, but several petite rescues where yes, life and death were options. One in the ocean with a SCUBA failure where my dive buddy got in trouble, panicked, and I had to rescue us both. (Divers usually die in pairs, one gets in trouble and winds up killing both.) Which is why I believe in PFD's with enough capacity to lift *two* people. Another dive rescue of myself, after a fishing net neatly wrapped me and tied me and I started drifting deeper into a deep channel on an outgoing current. A third from a whitewater trip, where my friend's non-swimmer gf took a bounce off the pontoon, into the water, and the two of us both reached her grab strap and deposited her back into the bottom of the raft before she'd figured out that she had been neck-deep overboard and gone.
If you've been trained to *act* without random thinking, to know the situation and responses possible, and simply follow the procedures, you just do it. Well, some people do it, some people panic and hoot and holler. Screening out the panicky types ahead of time makes a difference. I've found out from a number of minor incidents that I don't have to worry about panicking, and that's not really uncommon. Afterwards....I may need a long cold drink. Now, put a roach in my bedding and I may get too upset to sleep that night. But MOB?
If your crew has taken it seriously, you have a plan and when it is needed you execute it. You don't have a crisis until and unless that execution fails. Or, people start to panic.
"I wish we had had a Lifesling or some other type of hoisting harness,"
We keep a dedicated 4-part block and tackle rigged with a snap shackle on the "top" block. If the event of a MOB, lifesling or not, that's so that once we "have" the MOB, we can snap on the shackle to the boom, swing it out over the side, and even one person can hoist away and recover the MOB, clear of the hull. That might not be the option to choose--but we keep it available because it very well might be, and it requires no de-rigging or fiddling with any other part of the boat.
The hardest part of a MOB recovery may very well be getting the MOB into the boat--without slamming the hull against them. I've spent enough time in the water next to boats to know that even with a 2-3 chop and everyone alert, that damned hull wants to crack heads.