Unfortunately, my phone was stolen yesterday and now I'm back to using a dumbphone until I can find something better.
The last time there was any system instability at all was early in the life of the Nexus One. The OS has been absolutely rock solid since.
Of course apps crash on occasion, just as they crash on my 3rd gen iPad and 5th gen iPod Touch. The system stability ruse, however, is noise.
By crashing I mean: device reboots suddenly, which is of course a huge improvement over the 2.x days where the device would lock up completely, forcing you to take out the battery.
I have no experience with more recent devices, where it might be even better.
During 2012 I have been using both a Galaxy Nexus and a 4S as my main phone and at least MY galaxy was much crashier than the iPhone which is the origin of the joke.
The remark was intended as a joke, not as stating fact because I only have two devices to compare. Thankfully, it was clearly marked as such though.