Happy to do my part for the R182. I'd expect the results for the non-retractable 182 to be substantially different (worse).
Some other thoughts/comments...
1. Re Backpacker's caveat/disclaimer: according to a thread over on the Cessna Pilot's Association, there are quite a lot of fatalities even WITH an instructor on board. So I think that should be "...with an instructor who has extensive experience with this manouevre". (I still don't really understand WHY - it requires precise flying but nothing extraordinary. Not something for a 100hr PPL but a CPL/FI with a few hundred hours should be able to do it safely).
2. I flew mine with a teardrop, i.e. initial turn of <135 degress heading back for the departure end of the runway, then another small (<45 deg) turn to align with the runway. The shape described by Genghis will leave you further from the runway end. Which would be good if you were a bit higher - when I tried it at 800' on a 4000' runway, I was way too far down the runway and did not land.
3. I'm a bit puzzled by the reaction time issue. Even 2.4S strikes me as a lot, and certainly 4S. If you're flying a Robinson 22 (heli) and the engine stops, you most certainly don't have that long before the rotor stalls and you plummet earthwards. But people do survive for-real engine failures in them. (Admittedly quite a few haven't). Part of it I think is being "wired for failure". (For example there's a spot where I know perfectly well that the engine will "fail" when I'm flying the heli, and my reactions are correspondingly good. The goal of course is to be that good no matter when). On take-off, good training is to be expecting it to suddenly get quieter. The one time it did happen to me, I was pointed back to the nearest airport in a LOT less than 4S. (It was only a brief engine hesitation and I was at altitude).
4. I respect Mark1234's experimental results, but I'd also say that for a repeatable, survivable technique, going initially to 60 degrees is (in my plane anyway) a LOT harder than 45. I was losing 10 knots on the initial roll then finding it hard not to pick up a 10 knot surplus (i.e. gaining 20 knots) as the nose dropped. It was quite uncomfortable - for someone with no acro experience or not *extremely* comfortable with the handling of the plane, it could be terrifying.