This is the best advice I've seen in this ongoing saga. Paralysis through over-analysis. Every salesman's nightmare client.
Hence I haven't spoken to any sales people yet.
And you were the one I figured would be given me conclusive advice over whether or not an older entry level full frame camera is better or worse than a newer enthusiast APS-C camera.
As a former camera salesman, I have a very strong hunch that my opinion would likely be discarded as soon as a competing article or blog post or fanboy comment were to be taken into consideration. DxO Mark can tell you what camera has a better sensor than another camera; there are older semi-pro-level FF cameras now for $350 to $450 (Canon 5D, Nikon D700)..but you said you don't want to buy a used camera. So...there's no point in even answering strawman questions if, as you stated, plainly, you do NOT want to buy a used camera.
You do not want an older entry level FF apparently. You wrote ,"
I'm reluctant to buy used. I'd just like to get the best camera I can get new. May not be a rational choice but that's my instinct."
I've been around camera buyers, camera users, and forum people for a long time. Forty years or so. I know what's going on here. I'm pretty familiar with personality types and buyer types and being afraid to make the wrong decision and wanting to have EVERYTHING be the best it can be. For $700 to $1,400. You need to make a decision at some point. You are indeed, struggling to decide, regarding multiple aspects of your future purchase. Brand, format,style,feature set,new or used or refurbished, budget level, and so on. You are in a situation that many of us have seen, multiple times. I've stated my recommendations a couple of times, but really, I'm done with advice-giving. I wish I could help, but it's clear that the time to make the decision has come. Or not. Perhaps more time would help clarify this purchase. Maybe try a rental...
You live withing a short drive of two of the world's largest camera stores.
Adorama and
B&H Photo have mirrorless, d-slr's, APS-C, FF,FX,and m4/3, new, and used, and refurbished, Canon,Nikon,Fuji,Sony,Pentax,and Olympus, Panasonic, and so on. Maybe some actual, real hands-on time with some cameras and lenses would help narrow down the possible choices?
Just get a good camera, that's 30% of it. The other 70% is your skill and artistic vision.