Wow that was a really informative post, thanks! I only have a question about one thing- do the hard plastic cases protect the hinge? I've been using duraflexi clear cases for my O3DS and N3DS currently, but they don't cover the hinge, and I think the system I showed in the picture might not have been cracked if I'd protected the hinge (although it was on the inside, so you never know).
From the reviews, I've heard that the duraflexi protectors are less likely to cause scratches (although they've also scratched their fair share of systems) because they're flexible. Even though they're flexible, they protect the system well enough, at least in my experience this past year, except for the hinge, as I've mentioned. Do you ever take the case off to clean the system? And have you experienced any problems with scratching by your clear plastic case? Also, which brand of plastic case do you use?
Also, since you carry your n3ds with you in your purse, how gentle are you with your purse? Because, as I've mentioned, I'm pretty sure that helped crack my system too.
Thanks again!