Swapping W4S to Pass Labs XA- worth it?

Not sure where this 30kR input figure is coming from, but the 30.8 is 50kR in SE. 

Beyond that, I have a difficult time suggesting someone buy a class A amp and operating it in class AB a significant portion of the time. We're talking about an amp that's making 1% distortion at 30 watts. At 40 watts that number has probably doubled. And what are we calling clipping? Because I can promise you the output devices themselves are clipping at 40 watts. I have no doubt this amp will belt out way more than it's rated power, but that's not it's intended use. That's how the X series is intended to be used. I'm more concerned than I would normally be since the OP mentioned piping HT audio though this thing. I'm not saying don't buy it or try it. I'm just pointing out the things that I think should be considered. 

Tell us what the Pass would have to do that your current amp doesn't do that to you would make it worth the change?  I imagine they will sound slightly different, but without knowing you goals, or even the rest of your system, it's hard for anyone to say whether changing will be a good decision.

It really appears strange that you seem to want to run the Pass amp in A/B mode.

Stereophile measurements of 30.5 shows quite different numbers then 1% at 30 watts, in fact extremely different. I think 1% is at clipping when in AB. Here are those charts. https://www.stereophile.com/images/archivesart/509Pasfig4.jpg

I am not "planning to run it in AB mode", I just want to ake sure it does not clip in HT mode. I never listen to stereo at very loud volume.
As far a goal - I may be like more "liquid" presentation of some music, which in my case is small ensemble modern classical music, opera, small jazz ensembles and jazz vocals, and classic progressive rock.

For stereo listening I am planning directly feeding amp from AYON CD-5.

Well, I decided to pull a trigger on used 30.5 (late build, less then 2 years old). 30.8 is simply too big for my rack and will stick out too far. Will report results when all received and set up )))

PS I am not using preamp, instead I am switching amp inputs via Rolls SS32 switch, a very well build simple device

The numbers I tossed out there are what Pass Labs published on their website for XA30.8. I'm just talking from the experience of having built a Pass F5 and used it with not wildly dissimilar speakers. When I had that thing biased at 1.1 amp it clipped and it didn't sound it's best. It sounded hard and brittle. But I listen kinda loud. The thing has always sounded very good compared to lots of other amps. I'm just saying I'd be cautious. Take it or leave it.