Disclaimer: I have not bought any new freight cars since 2014, when my fleet reached ~800 or so. I have assembled over 120 Accurail cars, mostly PS ribside covered hoppers and ACF covered hoppers; with a few boxcars thrown in. All kits made since about 2000 come with Accumate couplers which work well with Kadee, but they are made of plastic, a negative for some modelers. I have never had one fail, but I have lost a trip pin or three before I figured out to add a dab of super glue when assembling them. Kadee couplers will drop in to any of them if that's your choice. Quality is excellent for what you are paying for them. The newer models have more detailed parts, but many are molded on. If you want to build a fleet of particular type cars, you can send them $4 for a decal sheet with 12 different numbers. This applies to cars bought before 2014, I don't know if it is still the same price since I haven't bought a new freight car since then. At that time they issued 4 car numbers for each model, so it was easy to get 16 different numbers with the decal sheet. Many more if you choose to cut the numbers apart and paste individual numbers. If I needed more, they would be my first choice as they are not fragile and they are not expensive. Plus they are made in America. They do have plastic wheels, or they did when I still bought them, but Kadee or Intermountain fit just fine. I'm sure others do as well.
Ease of assembly is dependent on the modeler's skill level. I can assemble most of them in under 20 minutes, plus the time needed to re-decal them.
I just looked at their website and using the order form inside the kits, it is still $4 for the decal sheet.
I will research tomorrow and find the last one that I documented in the Coffee Shop and will post that link here.