it will never be as good as a manual. beef it up and itll be in the same ballpark, but still slower.
you gotta dump hella money into them just to make them take power, and then they still dont shift fast.
not to mention they are harder to work on..
manuals are cheaper, faster, easier to work on, cheaper to upgrade/maintain, more fun, better gas mileage, more control of the car.
automatics are a luxuary thing.. easier to drive.
now powerglides.. mmm.. me n my friend built a 350 w/ a 3 speed powerglide. oooh boy, 1st gear till 55mph, 2nd till 120, 3rd till 185+.. not to mention instant shifting.