"Ltrain!" here, I am new to this forum but not new at all to o gauge trains. Here's my first topic: What are your thoughts on Lionel locos and rolling stock from the 1970s through 1990s (the MPC and LTI eras)? Here are my thoughts.
I bought a Lionel 8250 Santa Fe GP9 diesel about three years ago. I know some people say they "can't pull for nothing", but I find that if you know what to put behind it (ie: MPC Cars or anything with plastic trucks) they run and pull just fine. I pull an average of 8-10 cars made by Lionel MPC/LTI and even some old K-Line classic cars (with die-cast trucks!) and nary had a problem. Same goes for a more recent acquisition, a Lionel Rio Grande RS3 diesel with two truck mounted can motors, that will pull a good amount of lighter cars too.
For the freight cars, I've heard it said that the MPC models derail on tight curves quite easily. I have not found that to be the case if you run trains at a constant medium speed (around 12-14 volts on an average ZW or KW, both of which I use [that is still quite speedy as far as realism is concerned]).
All in all, I think these eras of Lionel are great values (price, price, price!) and all have served me quite well so far. Let's hear your thoughts!
Happy Railroading, Ltrain!