I picked up a T1815 from a guy n Stafford. It came out of a 2011 Tc. I might get the one in Rockville. It would be for my dads 2003 4runner. I am going to try the usb mod. I think I am going to end up putting the T1808 in my wifes highlander if nobody buys it from me. God bless her. She has been real patient while I nerded out over wiring diagrams all weekend.
The T1815 is nice for me because everything is on one knob. And that knob is large and easier to reach with my short arms. I'm no T Rex but I always found the stock headunit just out of comfortable reach.
The menu on the T1815 is pretty nice. You can scroll through the adjustments pretty fluidly. And it is highly adjustable for a radio intended for the masses. The sub input and subwoofer control from the headunit is a nice touch also. I just want to get the usb finished up. I am a little Leary about soldering to a circuit board.