Perhaps some simple reasoning. “I love my ARC REF 6. It's a great piece of equipment..”
you have achieved something many of us strive for!
A piece of equipment that in the context of your system, you LOVE! But like many relationships, there’s the “grass is always greener” syndrome. “I love my wife but….” lol. You may be looking for an excuse justifying what may turn into a dalliance. You are worried about changing tubes in five or ten years? AND, you admit to having replacements on hand! Yeeeow!
What about capicitors etc? I suppose you could try the Pass Labs unit before dumping your current “love” but you intimate it may be a one or the other situation. A real dilemma. I’ve faced the audiophile’s wandering ear problem. Maybe we, in this hobby, are destined to forever wander…unfulfilled!