I've owned mine for a little over a year, and it was maybe a bit over 6 months when I got it from the LFS, the LFS has kept one for a little over 3 or 4 years. Many online report having theirs for over 10 years.
A good number of the BP's do NOT live this long due to complications with their anatomy. But there is many who can.
Most of the websites about BP's I've read about them being peaceful has been just wrong for me. I keep mine with CA cichlids, it eats feeder guppies, she will attack firemouths she deems out of line, and can actually shut her mouth. She takes pellets from my hand, and will on occassion nip my hand when I move rocks or wood around.
I've always assumed it was a RD/Midas x Who Knows...