The SS auto or L99 stock does not give you the "sucked in the seat" feel. I test drove one awhile back stock and was not really impressed at all. Defenitely torquey and lazy feel but nothing like that, bam! shift, get sucked in the seat and bam! shift feel like the LS2 or LS1 used to give.
Are you sure the stock SS auto was not the supercharged version
Even the actual L99 owners say that the roller coaster "feel" is not there for stock, but modded and tuned I heard different
.
Iono.. maybe everybody's "feel" are different.