Opinions on Bluesound vs Sonos.

As you have found software is key for any sort of streaming or whole house audio. I used to have Sonos, sold it and never looked back. 
 

I use a Node to do all my streaming either from local files or internet. I use an external DAC and separates like any regular mid to high end stereo. I am not a fan of the Sonos amps as they are way overpriced but are convenient. 
 

It is easy to use any amp you want from the Node and another option here (different software) is the Wiim Amp which can prob drive the speakers as well or better than the Sonos amp and is a streamer too. I have no other bluesound products as many brands can easily be used with the Node. 
 

FWIW, you can run your existing Sonos speakers with JRiver software. The Sonos speakers are renderers or endpoints, I forget and JRiver sees them. Since JRiver sees them you can play thru them. Gapless playback is not reliable tho. JRiver software is pretty good and there is an iOS version (App Store) which I used to use to control the speakers.
 

The bluesound software I like and is generally found to be easy to use. I have not used the software the Wiim user do tho. And as you know Sonos has blown two major software releases in the last few years.

Thanks.

One of the purposes that the Sonos Amp serves is that it is incredibly discrete. One unit. Easy to hide. This is important because those are the terms set by my wife to put the speakers in our fairly formal living room. So I would prefer single unit discreteness and single unit simplicity.

The Bluesound Powernode is $950. The Sonos Amp is $700 and claims to be 4 ohm stable and 250 watts at 4 ohms (which is unlikely) but still a lot more than the potential 160 watts into 4 ohms of the Powernode.

The Bluesound Node is $500 and I could pair it with a small amp like a PS Audio Sprout or a Peachtree Audio GaN1 (they bundle it with a Node for $1700) or maybe something from Schiit. But that's going to put the total way over the Sonos Amp and over the Powernode as well.

I may start a separate thread about people's experience with the Powernode.

Question- does anyone know if the Node will power-on or wake up an attached amp so that no remote is needed?

After doing a little research I do not think the Powernode is an option for me. It very well may be a better amp than the Sonos Amp for the types of speakers the Powernode is intended to drive.

However, Bluesound have not (and apparently will not) release specs regarding the ability or capability of the Powernode to drive 4 ohm speakers.

So if I go with Bluesound it will have to be with a Node and a separate amp.

I think you are missing out on a lot driving those speakers with Sonos or Bluesound amps. Stick with Sonos if you like it, they will fix their problems. I suggest using a Sonos Port connected to a decent integrated that does well at 4 ohms. 
 

That said, I have Sonos all over my house, but removed it from my main system after I tried a different streamer and realized I could do a lot better.