I am running a Aquamist/Shurflow direct port WI system on my 2g Talon with extremely good results. My web page gives a quick description of the way mine is set up
http://lokmeup.iwolfe.com/Talon/WaterInjection.htm
I am running 26-28psi, at a WBO2 reading of 11.4-1AFR, corrected 11.8:1AFR, at +3* timing, with zero to little knock retard (~.4), flowing 58-59lbs/min airflow throught the engine and this is all on 91octane pumpgas.
Before going direct port, I was running the same setup with approximately the same amount of H2O/Meth injection, but was getting 3* of knock retard when I tried these higher boost pressures.
..for me, direct port made ALL THE DIFFERENCE!!
Ron