Like Guidocorona says: when an amp can reveal all the layers/diversity in sound and combined with a deep and wide stage with an intimate physical stage this is what you need and want.
Like more power wil give you always more control and grip. It is never a negative thing, so no worries about it.
In the beginning I prefered Pass XA amps, but based on my insight and knowledge these days I can create a higher level with an X series amp.
This is also based on the fact it has more power. I can reveal more details in the high freq. with it. I can create the same sound of a XA amp out of a X series amp. But I add it with more control/grip and details in the high freq.
You need to understand the properties to create the benefit with the X series over the XA series. Properties will always be important to understand the sound and stage. And to use it maximum.
I work by Tru-Fi, which are 8 parameters you judge sound for. When you listen to Pass labs pre/power combination you will hwar by Tru-Fi that it is incomplete/
This means that a part or more parts of Tru-Fi are missing. So what is missing?
instruments and voices are in real very small and direct. Almost all shows and in shops you see that instrumentd and voices are too big in proportion. Beside this the black level is nog that good.
When you would use a pre amp what can create an intimate and realistic individual focus you will experience the music at a more emotional level.
At the end you need all the different aspects/properties of sound what can be revealed when it is complete.