How would you upgrade my entry level system?

Thanks for the responses.
Guess I have some thinking to do.
short term: try Tidal streaming. Consider non Sonus option. 
Medium term: consider upgrade on speakers and then build new system.
I like the existing sound.
would just like to more captivated, can't articulate it any better than that.

Get a pair of Tekton DI's for $3K and sell or put those Audiovectors in another room! Changing speakers will make the most difference (and improvement) over anything else! Honest!

And quit streaming, if you want to be captivated...

My thoughts:

1) System setup. Have you spent time dialing in the speaker and listening position?
2) Room Treatments- Without knowing anything about your room it is hard to suggest, but often they can make an tremendous difference. With GIK you can get their Room Kits starting at under $600, and if you send photos and measurements of your room, GIK will suggest placement (they do a lot of professional audio installations and know their stuff).  
3) Absolutely upgrade your streaming service. You can get CD quality from Deezer, Tidal, or Qobuz. Tidal offers some higher resolution streaming, but is more focused on MQA now (you can research MQA yourself, the short is it is a highly debated area of audio) and Qobuz offers hi resolution streaming.
4) With the Sonos, you can get pretty good sound out of it if you use an outboard DAC, but it is limited to 48khz, so no high res streaming. If you keep keep the Sonos, I would try a Schiit Modi Multibit or Bifrost DAC. That said, moving up to something like a Bluesound streamer with an outboard DAC is worth doing.

I would look for some gently used equipment. Maggie 1.7i speakers about $1400, Parasound Halo integrated $1600 a good sub $700 and you'll have some great equipment and sound to match with money left over.