Well, I drove a 2012 Impala rental for six months back in, um, 2012. Yes, it has 300hp, but no way you'll mistake for any sort of performance car. My 2008 Impala SS made 303hp stock and would blow the doors off the 2012. My G8 would blow the doors off the Impala SS. No comparison.
The 2012 Impala was not particularly quick. Again, 300hp, but that power's not available until the higher RPMs and it took a while for the car to get there.
2009 SRM Premium and Sport Packages, Kooks 1 7/8" LTs w/ Cats, Corsa Cat-Back, Pat G Tune, CTS-V Brembos, RotoFab CAI, GXP Diffuser, Holden SS Steering Wheel, Holden Omega iQ Head Unit, VG Sharkfin, Homelink