David-
Although I agree with Bill, I see what you're saying about not having any realworld data to argue whether the -9 is "strong enough" compared to your Cessna. (I too have flown a 182 a lot, so I know what you're saying when you like seeing those struts out there under the wing, even if it may just be psychological).
However, you seem to be zeroing in on one aspect of safety that, in reality, is the least likely aspect you need to be worried about. When's the last time you hit turbulence that exceeded 4.4g? I've hit some bone-jarring bumps that I swore must have been 6-7g. After I looked out at the wings to see if they were still attached, what did the meter say? Less than 2.0. If one were likely to hit turbulence that was capable of breaking the airframe, I would blame that (in MOST cases) on the pilot's poor pre-flighting and decision-making, not the airframe. Van's has no record of airframes breaking up because of turbulence. The relatively few structural issues seem to have been pilot-induced. I would doubt that the -9 would fare any worse.
We all look at choices differently, but I too was very interested in issues of safety. Consider the following (all numbers taken from the cafefoundation.org testing reports):
Stall speed: about 10% less on the -9. Since the short-wing versions stall pretty slow to begin with, this may seem like no big deal. However, survivability in an impact does not vary in a straight line with speed. Any decrease in speed will exponentially increase survivability. So that 10% drop in speed probably means something more than a 10% greater rate of survivability. (I saw a chart on this once--if anybody knows where it is I'd love to have a copy). Thus, those 7mph difference between the 9 and it's short-wing cousins may mean something in terms of real life survivability.
Glide ratio: For the 9 it is 12:1. For the short wing versions 9:1. If you have an engine out would you like to be able to glide 33% farther?
Sink rate: For the 9 it is about 600fpm. For the short-wing versions at least 1000fpm (on a good day). That means in the -9 you have almost twice the amount of time to troubleshoot problems.
Again, these were only the factors that informed my decision given the type of flying I do and where I do it. Others may be more concerned about other factors, and that's fine, but I think it's important to focus on those possibilities that are most likely. Is engine trouble or fuel starvation more likely than airframe-breaking turbulence? I think accident reports would bear this out.
Just my thoughts (and my signature suggests a built-in bias)
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