I have three different versions of the Atlas trolley. My take is this:
1. Original Industrial Rail version ran dependably for a while, then the nylon gears stripped at the axles and failed. Good electronics, Dependable Bump-n-go, Bad Gears in the trucks.
2. Early Version by Atlas (Boston Elevated Livery) has run very dependably for many years. Failed recently when the electronics seemed to give out. ( Runs OK for a while, then goes into a very labored slow speed.) Good Electronics (For many years), Dependable Bump-n-go (I don't recall any failures) and Excellent gearing in the trucks.
3. Newer Version by Atlas (Happy Holidays Livery) runs very erratically. High speed, just bumps into the bumper with wheels spinning. Low speed, sometimes reverses, but stalls against the bumper about 25% of the time. I took it back to the store and the replacement unit had the same characteristics. Poor Electronics, Erratic Bump-n-go, Excellent gearing in the trucks.
I am tempted to try to salvage the new trucks and put them on the old Industrial Rail car. Not sure if they fit....
I was able to find another Boston Elevated early run Atlas and it is running beautifully now.
I also bought an MTH Railking 4-wheeler (Pittsburgh Railways) and it is running the best of all the trolleys I own. It has no electronics, just a simple slide switch. Ran for 7 hours straight at the club open house without a hitch.
I hope this is helpful. The visitors always enjoy the action of the bump-n-go's and the aspiring lawyers must LOVE the potential whiplash settlements for the tiny passengers!
Andy Zalewski, Past President, Boston Metro Hi-Railers