I've mentioned this before, but I work for the best contractors around and in the nicest homes around. The area I work in demands nothing but the best...and they are willing to pay for it. It's kind of a "I don't care about the cost....will it work ?" attitude.
Almost every home I work in is sprayed.
And yes, they often spay my ducts as well ...area permitting.
I have to use HRV's in these homes because of their tightness....but also smaller equipment.
I like the HRV fact because I can now control all the air in my home as I see fit....be it the air system,venting,and now even the air coming in.
These homes are QUITE comfortable. I probably can't describe the difference to you on a computer, but to walk into one of these homes I work in....you can just feel the difference.
Sounds like a comercial 'huh ? hahahaa
They are also all radiant heat as well. Foam helps.
My two cents.