a2a gives you better recover time after a run, not so worried about heat soak, which is great if you run it very hard on the street or track.
Tooky, compare the et difference if you run 5 passes back to back and then the a2a back to back, then you will fully understand the difference.
the a2w system is kind of limiting as far as airflow goes also, won't really notice it on a mildly fast truck but you will on big horsepower numbers.
a2a are expensive and really only need to be on the big guys, unless you beat it real hard on the street and are worried about heatsoak. other than that a2w works fine, works even better if you do some mods like the cooler in the bed with ice and stuff, actually give you below ambient temps for the run, which is gooder. But still a little limiting on the airflow.
all this info is courtesy of the search button, I have neither the time nor money to put it to the test personally :-?

but have been reading extensive cause I am looking at alternative methods myself.