Ok, so here is what I know so far...
With the 4100 with the Avic-U260 there are limitations on what it can and can not do.
You can not plug your Android phone in and use the U260 Navi. It just will not do it, according to Pioneer.
The 7100 and 8100 can.
If I plug in my Android to just the USB2, I get the Android Auto.
If I use the Pioneer CD-AH200 (cables/adapters) (usually they are 60 or 30 bucks depending on who you buy them from, I got them for $10) and plug in my phone (Nexus 6) it does not recognize it. According to the Pioneer tech, it's a problem with my phone and other Nexus as well as some other brand phones. The solution is to buy yet ANOTHER adapter that plugs in the mini usb then into the phone. So you end up with about 20 feet of cables from behind your dash. (Ok maybe less but it's still not acceptable)
On a brighter note, I have also been attempting to get an external drive (platter and SSD) to play mp3s. I used my PC and my Mac to format and copy files to either drive. Using FAT32. It would always tell me the format was wrong.
SO, I formatted the 3T drive as NTFS , copied the files over, and it took about a minute but it's reading and playing the music.
The down side is that I have to use the USB2 port, making it impossible to plug in my phone for Android Auto.
So here is what I'd LOVE for Pioneer to look into...
First off: PLEASE put this info on your web site. You'll have less complaints and returns and the users will still buy I'm sure. I know I would have just forked out for the 7100 or 8100
2ND: Don't limit what each port can do. This deals with Car Play and Android Auto and being able to use what ever storage device for music.
For those with iPhones putting an external drive on USB2 is fine, but if they have an iPod as well, they can't use it. For those with Android, putting the Android on USB2 does not allow for anything but an iPod on USB1, when I could have put ALL my music on USB1 with an external drive.
Allow both ports to do both things.
Don't tell me you can't do it, I"d tell you that you are not a good programmer if you can't do that.
And as far as the Navi, I haven't seen anything that deals with adding POI's or Routes that is very simple
with the 260, I have to take out the SD card and then use Navextras to update/add.
Because there is already an SD slot on the machine, it would be better to copy the files there, and then have a menu item to update the SD card on the 260. Luckily I had the installer put it where I could access it, but I'm sure most people don't think to do that.