I have the Fidelios and they are the original Model(really haven't had desire to upgrade or change). At the time when I auditioned them the Parsifal had a different Tweeter but I think the same midrange drivers. The Fidelios were considered a lot easier load to drive than the Parsifals and mine have a minimum of 6 ohm impedance. If you are thinking about running with low to mid wattage tubes I would consider the Fidelios. I currently am using a JOTA with 300 BXL's and around 23 watts.My listening room is about 12x 26. They sound great to me and yes they are very coherent, I get great depth and soundstaging as well. If your amps are capable and your room is at least moderate size, the Parsifels are still considered in many eyes to be one of the best out there but pricey compared to the Fidelios. You do see good deals occasionally come up here on AGON on both speakers. good luck,
Capeman
Capeman