Sorry, but for me, I think the speed alone wouldn't do it for me, because IMHO, that older generation Vette looks pretty outdated inside and out, has those tacky pop up halogen headlights (you've got Xenons), and reminds me of a Chevy Camaro. I think it would be a great addition to your stable, but not a replacement for the Porsche. Plus, it's not a convertible!
If I had to give up the Boxster for another car (non Porsche), and wanted some straight line speed, then it would probably be an M3 cab.