Not really. Exactly what about BBM's behavior makes it "secure" and "stable?" The app doesn't crash, ever for me. And if anything, the fact that
if an attempt to send via iMessage fails, it will retry as SMS, would seem to me to make it a more reliable method of messaging... which I guess translates to better "stability."
As far as "security" on RIM's networks: it was a useful argument in 2002, but secure data traffic is no longer exclusive to them.
There's a whole support document that explains the encryption and privacy measures used in iCloud, and that level of openness that makes me feel more knowledgeable and "secure" in using that over BBM, where RIM will gladly repeat the "secure" buzzword over and over, but not really explain in too much detail
how they make their network "secure."
And then there's things like this:
http://www.bloomberg.com/news/2010-...tedly-reach-messaging-agreement-u-s-says.html
And you realize that yeah... there's not a lot of security in BBM, really. Not that I would exapect iMessage to be fully immune to that level of scrutiny if a government really wanted to, but I think this shows that RIM really does a disservice to its users by continuing to let them feel that using a BlackBerry is still more "secure" than other platforms.
Then there are the global, multi-day outages:
http://www.reuters.com/article/2011/10/12/us-blackberry-idUSTRE79B24Y20111012
Which would seem to blow gaping holes in the "stability" argument.