Here's why amps can be more important than speaker

I disagree as well. Ditto Bomarc. I am surprised B&W said something like that - oh well...glad I sold mine!

If you drive your amp hard, distortion will be worse than the spec you see on the paper. Those are measured by a constant resistance load, I think, and the signal level they measured are of course at easy power level (which makes numbers looking good). But for real application, amp drives real speakers at pretty high power/current level. The speakers are much tuffer load, depending on frequency and their own distortions are not small even at easy power level. In engineer's words, both are working at nonlinear regions, and those numbers measured at more linear level (lower current and linear load) do not mean much in real life listening. You can use those numbers as reference but should not trust them more than your ears.
I would trust those spec's on digital equippments more, those are more linear devices, 0 or 1, and you can't lie about how many bits they are and what sampling frequency is.
If they can provide more inf on jittering noise then that would be a good judgement of transport on paper. The only problem is when it gets down to DAC and output state, analog parts come in and the nonlinear effects kick in again.

Does B&W produce a high resolution speakers for 2ch music anymore or just mains center and rears?

I have been buying audio gear for 26 years, and I can honestly say I've never bought anything based on the printed specs. I have this quaint way of always trusting my ears.

The printed specs to me are just a marketing gimmick.

I don't know what the relationships are between the THD and the sound but some of the best SE tube amps I heard have over 3% THD.