OK, Everything is connected and installed, so here's what I found:
After spending a couple of hours Thursday evening soldering up all the connections for the assorted harnesses (PAC C2R-FRD1, PAC SWI-RC, and Head Unit harness) I was ready to go Friday afternoon. Just about everything had a home on the PAC harness. The only exceptions were the MUTE wire on the Pioneer harness, and the VSS wire on the PAC harness. The new HU has no VSS-type system that I am aware of, so I just capped that off. Also, the PAC harness has a connection for both Amp Turn-On and Power Antenna, while the Pioneer harness has only one "remote control" lead (which if you read the manual is for amp/antenna turn on). I only connected the Amp wire, and taped off the other.
Disassembled the console and trim, pulled out the old unit, plugged the three connections in, and it was up and running. The PAC harness has 2 RCA plugs for SUB OUT. I don't know if either or both are required, but I went ahead and connected both. Reconnected my battery, and proceeded to program the SWI-RC (if you get one of these, make sure you use PAC's configurator on their website to generate instructions specific to both vehicle and HU - it works great and is much more clear than what's included with the unit!). Programming went smoothly, and steering wheel controls work perfectly.
At this point the only thing left to do was to route the wire for the external microphone, which obviously has no connections on the harness. This took longer than everything else combined, as I ran it through the dash, up the A-pillar, and to the visor. Put everything back together, and started playing with it.
Operation is awesome. Sounds beautiful, easy to use. My only complaints are these:
1. The DIM feature does not appear to be doing anything. I *know* I connected the "illumination" wires properly and got a good solder on them. When the headlights turn on or off, the HU does not appear to change much.
2. The microphone is insanely oversensitive. There is a setting on the HU for send volume, but even turned all the way down you still sound really loud to the other party. I tried to mitigate this by angling the mic away, etc. Still needs more attention, but it also might be my phone. No idea where to change that in Android though.
3. Pandora works ONLY with an iPhone. The Pandora app on Android does not connect to it. I hope Pioneer updates this in the future.
4. Music on a USB key MUST be in a folder (not the root of the USB drive). Otherwise the HU gives a format error.
All-in-all, I am very happy with the way the PAC adapter worked, with the exception of the lighting dimmer issue. RAP works as it should, and everything sounds beautiful.
Incidentally, I bought this HU from Crutchfield, and they included the trim/install kit. Fits absolutely perfectly.