jcs,
I think the Hegal is a great amp and I have a buddy who loves the built in DAC. My guess is that with the node, you were using the DAC in the node, which is inferior. If you use the Node only as a digital streamer and take a digital signal to your Hegel DAC, you should see improvement over the airplay which is compressed and the overall sound signature shouldn't change, since it is the DAC that gives you most of the character of sound going into your amp.
Now for speakers I'm gong to make a recommendation that may cause you to disregard all of my advice entirely. I see you have listed all the popular flavors of the day that you will find listed on Stereophile's recommended component list and they are the same speakers the come up in every speaker thread. They are good speakers. But they are strongly priced because they are trendy. In the sub 10K price range you can't beat Encores by Tekton. I bought a pair used. Liked them, thought about selling them to go to planar speakers, and ended up keeping them when a guy brought his tube amp over to try them out and I saw what they can do. Now I wouldn't think about trying to replace/improve on them in this price range. The midrange is absolutely spectacular with vocals and sax. Very efficient so your Hegel won't even break a sweat. the unique midrange composed of an array of tweeters absolutely shines.
I have spent quite a bit of time finding the right amp to drive them, focusing mostly on tube amps, but Hegel was a strong candidate for ss amps and I think they would pair very well with your amp. i have ended up with a Decware SET.
You have to have thick skin, because there is a lot of irrational hatred for them. But I've always been a bid of a rebel. Honestly, if this will bother you, then I don't recommend them, becaue you will see it ofter here. But I laugh and ignore it. And there are a lot of Ex B&W owners on the Tekton forums.
Other readers: please do not turn jcs's thread into a tekton bashing thread. We've been over that. I have acknowledeged that some people hate them, just make your recommendations and keep the thread productive.
Jerry