0-60 number is kind of meaningless in this class of cars...just simply play with the gear ratio you see a huge difference. At least I think one should look at 1/4 mile.
I will say 0-60 is still important number .. also 1/4 mile ..
In fact . HP may not be that important ..
Example .. SL63 .. 520 HP ... MORE then this 911 Turbo, but ~ 4.3 second 0-60mph ... which is 1.3 second slower then this JUST 500HP 911 Turbo .. 1/4 mile is also ~ 12.6 sec vs 11.5 ( est )
The new Camaro .. people love it .. 435 HP .. but still need 4.9 sec 0-60mph .. ( not bad ) vs a Boxster S .. 4.1 sec .. or 4.7 sec for a 135i ..
I know some car, can do a good number on 0-60mpg .. but not 1/4 mile ... such as Elise ... ( none SC ) 4.6 sec 0-60mph .. but 13.6 sec for 1/4 .. which is just so so ..
However, it is true that many car manu .. they love to make thier 0-60mph # looks good .. since that is what buyers will look at!
That is why, those newer PDK/DSG whatever gear box, make 0-60mph # look good! ( ie, Ferrari California with paddle shift, is as quick as F430 spider .. even the Cal is heavier and less power )
Also, on 997 Turbo now, AUTOMATIC ( old tiptronis ) offers better 0-60mph time .. ( 3.4 sec vs 3.5 sec on manual ) because the first gear in Auto ... JUST REACH 60mph .. that cuts sometimes .. but the fact is, if you drive both auto and manual 997 Turbo up to 300km/hr .. the manual one is actually quicker! ^_^