Hi, Im looking to upgrade my Yamaha dsp E800 & Marantz Pm66seKI sig. amp. Im after something with prologic2 and 6.1. I also listen to a lot of music so half decent stereo peformance is a must. Ive shortlisted Yammy 2400, Pioneer ax5i Harmon Kardon and Sony. Which of these amps provide the best all round peformance? Would any of the above produce a marked improvement over my marantz amp in stereo? Im leaning towards the pioneer at the mo but im worried that the stereo peformance might be a bit tame. Any suggestions?