I posted a while ago as was experiencing driveline wear on my new plastic bike - 10sp Veloce Bianchi Sempre Pro.
Due to the spacers being out of order on the cassette, it slipped out of certain gears for months until the bike shop decided to look at the problem and not blame the rider. I also broke the original chain, the cassette wore out and the freehub was replaced, the chainrings were on their way out too. I'd had enough at this point and sold the bike.
Once spacers were sorted on the cassette, it changed beautifully with short movements and I could get on and enjoy the ride. The down changes were excessively weighty - not harsh, but remember thinking "well they're going to wear out soon".
The consensus was the modern gear is disposable and the cut off for robustness was early 90s.
I have a early 90s Vetta with 8sp Veloce well worn now but still chugs along, after the International will do a restore as that will be my hammer bike.