depends on how early-
overall they track fine and run great but see my lower comment
the really earlly ones dont have pick up skids , which i think helps, the really eraly ones also have a unique LGB style coupler which cannot be made into mirror image couplers (hook on each loop) this can be importnat on rough track , as i often use this on certain cars and locos
i think as i recall too, they had an issue with the trailing truck, not sprung as i recall and therefore it didnt track as well
the other thing, personally, i dont care for about the older versions generally, but its not a big deal, is the clamshell motor block
if you get an old one you will need to take it open and re-lube-not a huge hurdle, but a much bigger endeavor than the later d shells
and really old parts can be harder to find is you need them-some of the original atyle screw on wheels are getting very scarce
i also prefer the later ones with 5v lights and smoke-just cos i like these features as well as headlight lens personally
the upside is that the old ones have metal drive assemblies which may be more robust than the later plastic ones
the early quality was great-as was the green livery
price is everything i think, if you can get one cheap in great condition i thinkyoull indeed be pleased, no matter