Has anything changed in firmware to stop that problem? I recently started using one of my old Model B REV 2 Pi's again, it was one that would restart if hot plugging USB devices. But it is not doing it any more.
I found out when I was stuck with a failed Internet connection and nothing plugged into it so was left with no recourse but to pull power which I was to lazy to do so I just plugged in a device thinking it would restart but it didn't. I tested multiple times and the Pi no longer crashes when plugging devices in. Some are ones that previously crashed it so I know they aren't just very low power.
Or could it be that in the time since I used this model regularly 2amp chargers have became common and I am using that now and it is good enough to keep the Pi working when hot plugging.