I own 5 scale GG1s; one Williams and 4 MTH. they are all great engines. The Williams looks and runs great and runs on smaller diameter curves than the MTH does. There is plenty of room inside if you want to upgrade to TMCCor DCS. The MTH are cast and are beautiful. They are equipped with DCS and two of them have pantagraphs that extend and retract automatically. My williams is a tuscan but my friend's brunswick green is a beautiful model too.
Here is my Williams GG1
Here are my MTH GG1s
The Williams GG1 has no problems pulling 8 passenger cars. Here's a video.
https://www.youtube.com/watch?...rQg&pbjreload=10