Truth be told i am a little leary about reducing their passive range. The two key things that made me do it was
1.) More escorts = more hydrophones in the water
2.) complaints about DD's running the user down from out of seemingly impossible ranges while attempting a submerged approach. If it hadn't have happened to me once, with no planes that i saw nearby, id have dismissed it.
While it will make the approach easier, I'm not too worried about it making evasion easier. It may, but i don't think by much since that's mainly a function of active sonar, and even with the reduced range, your still in earshot i think. We'll have to see.
I may in the future open the range on the passive sonar again, but for now, i felt it best to reduce it.
edit:
A 3rd item which i forgot to mention was that JP passive sonar was only good to about 2,000 meters or so if i remember correctly.
http://forum.kickinbak.com/viewtopic.php?f=29&t=1109
Even with the reduction, it's still better then reality.