Those UBR62’s are generally not considered to be a standout at their price.
I would look at the Ascend Sierra-LX and (if you can accommodate the size) the Wharfedale Linton 85 instead. And then for the amp… don’t get something where the streamer is built into the amp. An amp can last you for decades while a streamer is likely to have compatibility problems within 5 years. It’s stupid to have things of such different longevity built into the same box. Look at these instead:
https://emotiva.com/products/basx-ta1-stereo-preamp-dac-tuner-with-integrated-amplifier
https://www.amazon.com/WiiM-Pro-Chromecast-Multiroom-Compatible/dp/B0BJDY6D1W
$750 together. Better amplification than the Powernode + just as powerful streaming features + much more setup flexibility.
Spotify 320 is more than sufficient.
WiFi Streamer with a built in DAC:
I decided to revisit this issue today (it’s been about 2 years since I previously gave up on it). It seems that Denon, Spotify, and/or Amazon have no intention to make Alexa integration a reality for Spotify users. However, it does seem like there may be some more viable (and fairly inexpensive) workarounds available…
You might still have to switch on your AVR and set it to the correct input… But once that’s done, do you think the new WiiM Pro or the Echo Link would get the job done? Technically speaking, it seems like the WiiM Pro might be a superior, more versatile device — but I wonder if the Echo Link would inherently be more reliable with Alexa control since it’s an Amazon device. Can any of you share thoughts / experiences with either of these devices?
Your budget breakdown is a bit out of whack here. Speakers are the most important component of the system by far, and these options have you short-changing your speaker selection to overinvest in electronics.
Also, I would highly suggest you consider options where the streamer and the amplifier aren't built into one box. A streamer will probably last you 3-5 years before you end up first encountering software or network compatibility troubles... whereas an amp can last you decades. Binding them together makes no sense.
Here's a good example of a setup that would make more sense for your total budget: a pair of Revel M126Be speakers for $3900 (open box, full warranty, highly reputable seller), a MiniDSP Flex preamp (with measurement mic, Dirac, and XLR upgrades) for $844, an Audiophonics MPA-S250NC power amplifier for about $490 shipped to the US, and a Wiim Pro streamer for $150.
Total price for this stuff would be about $5400, so right in line with the KEF + Cambridge combo. And you would be getting better speakers, more power headroom, and more flexibility.
You would mainly be losing out on the fancy amplifier faceplate, and the screen on it to display album art. And you'd also lose HDMI ARC... but that doesn't matter because HDMI ARC is only needed for high-bandwidth surround formats. For stereo use it has zero practical advantages over S/PDIF.