Can you give me a quick rundown on why the PAC units isn't ideal? I looked and didn't see any threads on this topic.
we covered this all in the GEN TOO threads.
Be cause it is still just taking its signal off the high-level outputs of the factory amp. So you are stuck with what ever signal processing is being done by the factory system.
The factory system rolls of bass at high volumes to protect speakers and warranty claims. just adding an amp and subs to the factory system is a waste of time and money. To get any decent bass at high volumes you have to crank the gains up, and at low volumes, your system will be very bass heavy.
Zen A2B ties into the factory can-bus system. pure clean digital input, what you do with that signal is up to you. but you are essentially taking the ford amp out of the signal path.