I should probably clarify what punch means to me.
http://www.youtube.com/watch?v=x6q_ZosDwRY
That's me playing the same bass I'm talking about (everything's stock on the bass and the EQ is flat). Fast forward to 4:40 and don't mind all of the suck. You can hear though that the bass has a sort of kick on all of the popped notes. I'm just looking for that again.
The ironic part about all this is that the Sterling I'm playing there has the stock set of strings that came on the bass. I put the same gauge and type of strings back on again (Slinkies item number 2834) and I just don't get the same sound, even with EQ tweaking.