Gene

This a great news!  Please keep us updated on progress.

Forgive the reflections, it’s so sunny! 

Heres my take, but please realize that C4 is a dealer platform so having a dealer you can rely on, helps in the overall experience.
Getting multiple quotes is good.
Networking
Ruckus is excellent and I have had no problems for years; prior had issues with Araknis but if the dealer is supporting, shouldn't have any issues.  The unifi debate I won't get into but realize C4 is dealer based so go with something that is recommended so its easily supported (unless your supporting it yourself). 
Surveillance
Cameras are all over but Luma works well.  I prefer a separate app although many can be integrated into C4 for programming which is helpful (per your request).
Distributed Audio
Your solution is fine as long as its background music; You can spend alot of money on audio, but from your statement of expectations, is valid and it works.
Security
Utilize what the dealer wishes to recommened and view demo with dealer;  You and your wife's expectations are easily met, but having it integrated correctly helps with the process and support.
Lighting
C4 or Lutron work great; You can reduce wall clutter with keypads etc...  Again, planning with a dealer is key esepecially during construction.
Locks
Do you have a style that works with the home; that would determine which brand you might choose; Your list is accurate, but its getting them that sometimes a pain (supply chain).
HVAC
Both work well; Your correct on looks for Aprilaire but Ecobee works fine too.  Both integrate fine.
Control, Rack
I would recommend you go with one of the NEW controllers to be released if your planning now (core); run Cat-6 everywhere you can; You didn't discuss distributed video; WattBox, UPS, etc...is just good practice and easily manageable if you have issues (dealer can help via remote).
https://www.strata-gee.com/snap-one-unleashes-an-array-of-new-products-at-virtual-partner-summit/

I saw that Apple will have an open API for Siri integration and was thinking the same thing....we shall wait and see...  I don't hold my breathe given it seems C4 is slow on jumping on that bandwagon and has Alexa integrated pretty well. Hopefully they will though.

I have Rachio and it works great with C4.  As for landscape lighting, I have a volt transformer and use their LED bulbs and lighting with a Lutron RadioRA2 switch (https://www.voltlighting.com/). to turn it on at dusk and off at dawn. Simple and reliable.
 

I have Rukus 520's in the attic, on my ceiling 2nd floor and basement. I'm Pittsburgh and haven't had an issue for 3 years (have the 520's).  No problems; great coverage; rock solid.

My guess is it's some sort of sales promotion, rebate program, etc... and not a product announcement.

https://www.voltlighting.com/
 
 

Thanks for the explanation Ryan.  I think overall, releasing a remote and moving forward is what C4 needed and although we all might complain about what could be better or how to change things, atleast they purchased a company and brought to market something rather quickly and things will only get better!  That has been stagnant before OS3 so onward we move...  Also, maybe by keeping the SR-260, it just will mean in the future (not distant future but future) a replacement will be made for it which will be a larger leap!  We can always hope!!!!
 

Thanks for the explanation Ryan.  I think overall, releasing a remote and moving forward is what C4 needed and although we all might complain about what could be better or how to change things, atleast they purchased a company and brought to market something rather quickly and things will only get better!  That has been stagnant before OS3 so onward we move...  Also, maybe by keeping the SR-260, it just will mean in the future (not distant future but future) a replacement will be made for it which will be a larger leap!  We can always hope!!!!
 

Thanks for the explanation Ryan.  I think overall, releasing a remote and moving forward is what C4 needed and although we all might complain about what could be better or how to change things, atleast they purchased a company and brought to market something rather quickly and things will only get better!  That has been stagnant before OS3 so onward we move...  Also, maybe by keeping the SR-260, it just will mean in the future (not distant future but future) a replacement will be made for it which will be a larger leap!  We can always hope!!!!
 

Most ppl don't buy an iPhone ever year