My entire collection is primarily MPC/Fundimensions. It all runs well and overall is as simple to repair as postwar Lionel. In its early years MPC faced an uphill climb on two counts -- first, Lionel had already been aggressively cutting costs and cutting back on quality in its final years. Second, times were moving on and the postwar materials and production methods had to at least partially change.
So there was a ramp-up period of both bringing back postwar engineering quality and adapting to more modern production realities. That's why there were some false starts with Delrin gear drives and early traction tire use. Today, those are solved problems and we tend to take them for granted, but the realities of those had to be worked out "the hard way" in the early years of MPC. By the late 1970's and early 1980's, MPC (now Fundimensions) was able to produce trains on par with postwar Lionel, but with more modern materials and with paintwork that was beyond what was possible in the postwar era.
If there was one manufacturing process used in the MPC/Fundimensions era that irked me, it was the use of an adhesive to connect wiring to the copper "wiper" pickups on trucks for the outer rail return side of electrical circuits. No solder -- the wire was held to the copper strip with a clear adhesive. It would either come loose, or it would get pulled into the braided wire by capillary action and harden, making the connection too stiff so the wire would break. It got to be routine for me to just re-work those connections with proper solder right out of the box. Somewhere along the way, I'm pretty sure solder returned, but not until I'd re-worked an entire Blue Comet and Chicago and Alton set, most Sound of Steam tenders, plus numerous cabooses. And then the problem with any factory-soldered connections on rolling stock items was all-too-frequent improper "cold" solder joint that would still fail. Soldering on locomotives' e-units and motors was generally fine. It was always the rolling stock that routinely had electrical quality control issues.
