From Pass X250,5 to 350,5 : what to expect?

Fatcataudio, do you expect much of a difference between x350.5 vs x600.5 vs xa160 for either a Wilson Watt Puppy 8 or a Sonus Faber Elipsa or the like? Pass Labs thinks the xa160 should have enough power to handle those speakers. I have my doubt. Yet that pure class A of the xa series is tempting at the 80 db sound level.

spatine, what efficiency and nominal (and minimum) impedance of your speakers? You will be very surprised at how little power you actually need if you listen at normal listening levels. I actually calculated the power my speakers needed at varying volumes, listening distances, and peak music levels. I was surprised to just how little power is required.

owned 350.5, 250.5 and 150.5

350.5 is smoother and also has more bass impact, 250.5 is brighter and bass is a little loose, transparency is about the same. Tried 87dB and 90Db speakers. I rather have 150.5 than 250.5

Spatine, I would go with a pair of the new XA.5 series as they double power as the ohms half. This may not be an issue, but since the Wilsons look like they are 4 ohms you would be doubling power, so in my book it would be a nice benefit if needed to get the XA.5 series. I would suggest the XA60.5 or the XA100.5. I don't think the added power of the XA160 is needed. please let me know if I can help at all.

I just have to ask if the 350W X350.5 is needed (vs X250.5) for Wilson, why do you think the 100W XA100.5 is enough? Secondly don't the XA and X.5 series (and not just XA.5) double their power going from an 8-ohm to a 4-ohm? Thirdly I heard the rumor that XA.5 is just a quick re-design of the XA. In other word, any changes would be minor given the cost factor. Is that true? Fourthly, we are talking about 75 db for rock music and 55-85 db for classical music. Are you sure that 100W is enough. Thank you.