I use similar logic when I settled on my R/T... coming from a 2006 R/T it was much faster just having the 8 speed and the Eagle heads/VVT. I was flirting with Scat Packs but it was so hard to find any V8 Charger without a sun roof.Which who needs to have even more punch at 70 MPH? LOL unless you run a lot of interstate, I suppose. That was another reason why I got the SP WB vs the HC..this is risky enough as far as getting into trouble. I haven't driven a HC, but I would be afraid that I would want to stretch its legs to really enjoy it. Much of what I have heard/read is that the 392 and HC are nearly identical until you get up into the speed as you had mentioned. (50-70 MPH)
Yesterday I was chatting with a neighbor that was hosting a youth church thing in his back yard and here comes a Hellcat Redeye Charger in Torred with no sun roof, he was dropping off his kid! Super nice guy just picked it up in March. I told him I had the junior starter kit right behind him! I asked him what he does in winter and he drive his stick shift Mazada 3!
Once I found a good V8 that was post 2017 with that active exhaust that was good enough for me... add in the fact it is a 2019 with the performance fasicas and even better.