I've sold my Portal Panache and kept the Cayin 265Ai. After about a month of testing both with the rest of my system I had to make a choice. The Panache is a terrific amplifier and is much more forgiving of so-so recordings. It's a bargain too. I liked the Cayin's more "in your face" way with vocals and the midrange in general. The high frequencies are more forward too and that's not quite as nice. The Cayin's much faster than the Panache, more dynamic and more resolving (that's not always a good thing). This might have to do with the class A topology.
These 2 amplifiers couldn't sound more different. It's literally night and day. I was used to the beautiful sound of the Panache so it really was a tough call but I just couldn't live without the more lively vocals the speakers were producing when paired with the 265Ai. They come alive.
That being said, I still think the Portal Panache will satisfy many audiophiles out there. It's definitely warmer, much less picky about recording quality and mates well with just about any other decent quality component. The Cayin is more fussy about what it is paired with and cabling. It gets HOT and is heavy as hell. I'll live with that cause the music on good recordings is addictive.