High-tech items like model trains are very complex. All those beautiful and amazing features we love can result in issues from time to time.
I have bought both NEW and USED locomotives and had more problems with brand-new ones than with models another hobbyist has previously owned. This has been true of locomotives bought from individuals or from resellers like Trainz. I have also observed that Lionel TMCC (Cab 1) engines from the early 2000s have been better when those were made in Korea (vs. China). The Koreans of course have a long background of excellence in (for years) brass and later plastic-bodied engines.
Trainz in the past have always UNDER-rated the products. But in 100% of my purchases the items were better- sometimes far better- than what was stated. In my most-recent experience, I just yesterday received a Lionel M1a Mountain from Trainz. They described the Mountain on "the auction site" as "functional".
What I got was a good price, packed and shipped carefully (and fast).
It was not perfect- had a bent tender axle- I straightened it. The IR connection between the loco and the tender was being disrupted- I tweaked the two parts for a reliable connection. It runs GREAT now. The only way these could have been found would be with a fair amount of time and testing on track. (But you don't get THAT with a brand-new one either.)
But no needing to return for warranty service, no time wasted on the phone with "Customer Service". Just a nice piece at a fair price. That was easily corrected. Kudos to Trainz!