What should my next upgrade be? Your best experience

Garbage in garbage out.  Start with upgrading the source not the output.  You listen to digital so make it better.  The Sonos upgrade feeding an outboard DAC will make your speakers sound better.  Digital components are very sensitive to AC power gremlins.  A better power conditioner should help clean up the digital signals.  If you can get a dealer to allow you to demo a Denali you will be amazed,

I am not convinced about the Sonos' inferiority. You produce no data to substantiate that its output would be garbage. Also, there is as yet no solid evidence that the difference with the sound from the Marantz is due to a problem with the Sonos, even if it is obvious that the Marantz is very good. Rather than buy yet another DAC when you already have an excellent one in the Marantz, the simplest solution would be to direct the digital output from the Sonos to the network connected Marantz (but it may be tricky getting that to work). Also, I am not so convinced that digital components have particular power supply isues if they are well designed.

It all depends on what your budget is and what level you are able and want to play on.  Digital is highly sensitive to power issues.  It doesn't matter if it's a 500 Chord Mojo (I own one) that's battery run or my Ayre QX5 that has a power conditioner built into it and has built in optical isolation etc....  I have friends who own the Bricasti DAC/amp as well as the Davinci mk 2.....all of them need the proper filtering and power cord.  Digital still has inherent problems and that's why a decent TT combo will still sound more musical and more natural than any digital out there.  There are some areas where digital can be outstanding and with better clocking and design, they are getting jitter to where it needs to be so timing isn't off as much.  

There are outstanding value DACs as well as good sources, but you must try them all together.  Digital is so finicky.  You can't just say source A is great for the money and DAC A is also great for the money and assume they can sound good together.  Too many things will play into that like your rooms power, connections between the two, the way they both are engineered and which connections are max'd by each product.  Then you take into account your wifi if you stream that way (hard wired is always best), which ethernet cable are you using and what type of isolation are you using if any, both internally or externally.

Just too many variables in play here.  I personally buy systems.  That's what I'v always done and I usually don't buy that often.  I will make some changes if I feel they are worth the money and if I have the money at the time (just upgraded from Vandy Treo's to Quatro CT as I felt they were THAT much better for me).  

When I help someone put together a system, I usually take the budget and figure out the best source for them and then look at speakers they may like to get an idea and then fill in with the amplification.  Pre amps to me are SOOOO important.  

Garbage in = garbage out is true, but a great source can be ruined by a DAC, amplification, mods, accessories, cables and or speakers.  Same with anything else in the chain that is down stream.  That's why so many folks audition speakers and fill in from there.  I've heard better sound, personally, from GREAT speakers, good amplification and a decent source. Conversely, I've heard not so great sound from a wonderful source feeding world class amps run through average speakers.  Again, JMHO 

I agree a good high resolution capable DAC will likely help here.  But the best upgrade I've done, short of replacing speakers, is to add left and right REL subwoofers.  Improved every aspect of sound quality including vocals.

Hello and thank you everybody! I have learned a lot from all of your posts and I have taken the time to reflect in what everyone has said, as I take all of your replies seriously. I also know they come with not only the passion we all have for Audio but the experience this passion comes with!
It seems to me a general consensus that I need to upgrade the streaming I have. It looks like I unfortunately cannot use the DAC in the UD7007 (which I’d love to do) because it does not have the correct inputs sadly.....
But you know what does?!?! A Marantz NA-11s1!!! lol I guess I’ll just dive in!
Here is the review for it and it does have both a Digital and Optical input but also a network that will rout the Sonos stream direct to its DAC, which by all means seems to be a pretty good unit?

https://www.stereophile.com/content/marantz-reference-na-11s1-network-audio-playerdac

Now, I’ve also heard the thoughts that I should look at the listening room. And I should and will! It is a A/V or should I say TV Room lol But I can see multiple areas that I can improve on, even if they are just small improvements they will improve the room never the less.

Now to the Sub suggestions.... I think I’ll wait on adding any subs to the system. I can honestly not say if and how much of an improvement adding Sub Woofers to the system will add? What I will say is that the PM-11s3 is VERY underrated at 100wpc into 8ohms and that it will double down. The Silver 8s are a 4ohm speaker that are getting just bullied by it and they play both loud and low. I’d describe them as a bottom up speaker. With the Silver 8s placed 20" or so off the back wall they provide very good bass. And very good bass at low volumes. This bass is fast, tight, and deep. I’m throughly happy with it! It shakes the floors 30’ away lol

Anyway, please let me know if you think looking to add a NA-11s1 is the right or wrong move as I appreciate your thoughts!

Thanks again, Charles