These are the numbers reported by Consumer Reports real-world tests of the manual/automatic xB. The percentage differences were added by me.

0-30 mph, sec. 3.4/4.0 15%
0-60 mph, sec. 10.4/11.4 9%
Quarter mile, sec. 17.9/18.7 4%
Quarter mile, mph 78/74 5%
45-65 mph, sec. 6.6/7.3 10%

My reading of these numbers leads me to conclude:

a) the manual's gear ratios favor low-speed acceleration (why the car "feels" faster with a manual);

b) the high-revving engine and shortish gear ratio in 5th provides better passing acceleration at "2-lane highway" speedsfor the manual;

c) for the sort of acceleration you commonly do to merge onto an interstate, the differences are, in the end, minor; both transmissions get you from a standing start up to 75mph or so within 5% of each other;

d) neither one of these models is what anyone would call "fast." A 5-10% improvement would still not make them "fast." 0-60 in more than 10 seconds is not fast. By any sensible measure, these numbers are adequate, serviceable, decent for an economy car, and no more than that.

RichC