Krell FPB-400cx vs. Pass 350.5 for Thiel 3.6

Hey Guys,
I am looking to upgrade my amplifier and have narrowed my choices to these two amplifiers. I want maximum performance and would like to know which amp is going to deliver the goods? :) I have found that the aspects I am looking for are more detail, a wider and deeper soundstage, and images with more substance and shape.

My current setup is as follows,

Thiel 3.6
Classe CP-50
Esoteric X-03
Parasound HCA-3500
Spacedeck/Nottingham Cartridge

You can check it out here,
http://forum.audiogon.com/cgi-bin/fr.pl?vevol&1208030380&view

Thanks,
Matt