I think people obsess too much over the automatic parking brake, sure it needs to be maintained and monitored, there are options to help with this like the Genie warning light system and Brazel's improved pressure switches. There are lots of other things that cost money to replace when they fail too, a new refrigerator will run, $1,400 or so, a roof top air conditioner will be around $1,000 and if a engine fails you will be looking at $12,000+.
Ike
p.s. I have a J71 APB in my 02 P32 Safari Trek, I carry a spare set of pressure switches, have and check my genie warning lights, and routinely check the pressure switches for leaks. So far I have put about 6,000 miles on the coach since buying it last year, and no APB problems yet.