They appear to have improved. I bought a new one ($1500 retail) 16 years ago, and it was JUNK. Every single plastic piece (thread guides, presser foot lifter, foot pedal, etc) broke within 5 years. I hated that machine, but after spending so much money, I was stuck with it. I bought it before we moved to a very remote area, so I couldn't get it serviced, either!! SO foolish.
So obviously they are getting better instead of deteriorating in quality.