I think your assessment was pretty fair, my father has a 1200 custom that I've been riding for the past week to give it some road time and the experience between the two is much different. I can't really attribute it to build quality, even though theyre both sportsters they are way different.
His is a 2004, rejetted carburetor and running upgraded air and exhaust, also the front sprocket was swapped out to increase low-end torque.
Mine is a 2017 with just a FP3 tuner installed.
From personal experience, the tuner definitely helped the bike run the way it should. The seat is terrible and after 10k miles I can confirm there is no "break-in" period for it. Hopefully the 2018 models have better seats, they look comfortable in person.
In terms of sound, I havent heard the new 2018 models in person and my fathers 1200 has V&H's straight shots so its hard to compare. My 2017 was pretty quiet even after being tuned, you can really hear the throttle open up now that I've got the big sucker intake on but its still pretty quiet.
It does seem that Harley has taken notice of the major complaints and tried to address them, the new seat, suspension, bars, and overall loudness. So I guess that lessens the "Harley Tax" but even if I had to start over I'd go with what I've got now.
Performance aside, I'm glad to have replaced the filter, the big dish was annoying and with mid controls it was pretty annoying on longer rides.