Hello Roger,
After 45 years in the hobby I still discover a few surprises now and then. I have owned hundreds of trains over the years, and they all have good and bad moments. On the subject of the Bachmann F9/F7 series, quality has ranged from really cheap toy-junk to very good hobby models, and sometimes a simultaneous mix. Most everyone remembers the pancake motor series tyhat ran from the late 1970s to the mid-1980s. The chassis and drive gear were equally abyssmal, especially with the "starter sets". Most people have forgotten the 1st generation (1970-76) F9s, U33/36s, and GP40s, which were hobby-quality models featuring can motors, heavy metal chassis, and 8-wheel drive.
Regarding the T-Kincade & Hawthorne F7s: I avoided buying these new primarily due to the outrageous prices targeting "art collectors" with deep pockets. All that notwithstanding, I was more interested the constuction quality. It has been my experience that most of the Hi-Definition Artwork was apparently applied to models specifally made with as little shell detail as possible. Ok, it makes sense that all the pretty artwork jazz would get lost and distorted on highly detailed bodywork such as side grills and the like. The chassis were, in many cases, very lightweight metal frames with no flywheels, and very little traction. But again, these were mostly going to be bought and displayed for appearances. By using their very bottom basline models, Bachmann was able to contract the "exclusive artwork" and not lose money. However, most hobbyists I know, myself included, are primarily interested in model quality as a whole, appearance details, pulling power, smooth motor operation, and operational longevity. The noverlty of the pretty artwork wears off quickly when the actual functionality doesn't measure up to the price tag. This is where I still find dissatisfaction with any and all of the Hawthorne merchandise. Especially when they started selling what appeared to be Spectrum series bodies, but still had the Bachman base-line chassis hiding underneath, and still sporting a premium "collectors edition" price tag. I have accidentally ended up with a few of these "imposters", as I refer to them, but thankfully not at the retail price. 30 years ago it was relatively easy to spot the bad ones from the good ones. Back in the 70's and 80s, price was a pretty fair indicator of the quality you could expect. Today it's not so cut and dry as some of us were previously used to. Nowadays, your more likely find out, too late, that you've bought a very pretty dust collector.
I will say this, Bachmann, to it's credit, has sucessfully hung on to multiple markets for way longer than some of its contemporaries from 40 years ago. Their sheer variety is staggering, really. Which is one reason I still have over 150 Bachmann locomotives, and still collect them to this day!