I'm curious what the OP is looking for sonically. Because sometimes an upgrade of a component isn't the solution, which is why I assume MC posted about Townshend.
I thought I wanted an upgrade path for my monoblocks until I realized what I wanted was better caps and better isolation. If the OP simply wants to buy more Pass components, well, that's a different question -- and a legitimate one. Just don't know what he/she is seeking.