The 2013 Cartel wont be too stiff. The highback is softer torsionally now so when you want to get out on the tips or tweak a grab you can. Personally I'd go for IPO's. The combo of the stiff frame and soft highback feels super good in my opinion. Perfect for a freestyley ride and they'd match up well with the Destroyer.
You're speaking of the K2 IPOs and not the Now IPOs correct?