I have had that happen (hesitation) when the O2 sensors were about to go
bad.

Air let into the engine with the throttle opening is supposed to cause more
gas (because the O2 senses it's running leaner).

Check your O2 sensors, in other words.

As for getting rear ended, that's just idiot drivers, not your car.

I've owned a 2006 OutBack with the 6 cylinder, and, now drive a 2007 Legacy
2.5 GT sedan.

On both, I've been troubled by the hesitation I experience, particularly
when I need the car to move (pulling out into traffic, passing on the
Interstate, etc.).  I've almost been rear-ended several times when my
get-up-and-go, didn't.

In fact, it was so bad on the OutBack, that I convinced Subaru of America to
let me trade it in, and, got the Legacy, which seems just as bad.

Don't get me wrong, there are times when I can press on the gas and the car
winds up and moves very impressively, but, quite often it's like the pedal
is disconnected from the engine.  And, I'm not sure if this is the engine or
the transmission not downshifting when required.  Doesn't make much
difference being in S or S# (S# just winds up further in RPM's).

Anyway, I was told by dealers, mechanics, and SoA, that "this was normal",
so, believed it was (just a bad implementation of drive by wire).

Then...I drove my wife's Forester 2.5 GT.  WHAT A DIFFERENCE!  This car's
acceleration is how I used to remember it being in other cars.  Absolutely
NO hesitation, responsive, and...peppy.  I would just rather have a sedan,
or, I'd think seriously about getting a Forester.

So, now that I know Subaru CAN make a car, even with turbo and drive by
wire, that's responsive, what's the issue with my Legacy?

Thanks.