Don't know if I like my XDI...
So I too installed the True Flow XDI canister in my '04 V6. I have to say, as far as Aftermarket parts go, this one is very well made, packaged, good directions, etc. It took me about 45 minutes to install the kit.
Interestingly enough, as soon as I started my car, (with a full tank of gas) my trip computer said I had a range of 385 miles, and it's never said any more than 350. I know this isn't exactly very accurate, but I found it interesting.
I then ran the car around my block. There is definitely a better deeper growl to the motor. However, when I hit WOT and the car spooled up from about 3500rpm to 5000, there is a HORRIBLE vibration and resonance from the airflow. I called True Flow, they were helpful up until the point they came back and said the tech said "for some reason, Toyota's are just loud..." OK... Well, I do notice a nice boost and from 3 tanks now, better gas milage, by 8-10% per tank.
I might actually put my stock back on, just because this thing is LOUD at WOT. Anyone else experiencing the same thing? Let me know.