I tend to have a Depression-era mentality and use things until they die (witness our 2002 Honda Odyssey with 225,000+ miles). The BlackBerry still does what I need it to do and has never had a problem. I don't like to surf the web on a handheld device (far prefer iPad, laptop and desktop for that), so what I use it for more than 90% of the time is phone, text and e-mail, all of which it does extremely well. And it has been essentially bullet proof, having survived drops, falls, driving rains, etc. I don't use apps, I'm not on FB or Twitter and I don't stream music (I have an iPod classic that is maxed out with some 25,000+ songs, and I listen to Sirius most of the time in the car).
From what I understand (very little), BlackBerry is still supposed to have the most secure e-mail system, which is the reason we have used it for work. Whatever it is, someone must still value their technology because Samsung just offered $7.5B to buy BlackBerry based on the strength of its technology patents.
My wife and two of my daughters have iPhones and we have an iPad, so I'm able to make use of them as needed as well.
Best of all, it's already "retro." I get lots of great, nostalgic looks from many people, and BlackBerry itself just released basically the same design, calling it the "Classic."
My last phone before this was the Motorola flip-phone, which I had for probably four years and missed dearly when it was gone.