As I have owned, run, and unfortunately, repaired them, I must respectfully say I do not consider them to be good at all. They have plastic wheel centers, which after some operation come loose on the axles and freely turn--thus messing up the valve gear quartering, etc., such that it won't run.
I've replaced all the drive axles on one before (the store, my employer, had the parts).
They were made from some time in the late 1960's on. The miserable ones I'm talking about were made through the '70's. They have 3 pole motors, and are quite common still today. The only good feature is with brushes sticking out of the back of the cab, they are easily replaced when needed.
You would be much better off to go on Ebay, spend the $250, or $275, or even the mid-1980's retail price of $350 to $375 for the Oriental Limited Powerhouse USRA 2-8-8-2 steam engine. Sometimes you can find them at only $250, new.
It is a "brass hybrid" from the era before hybrid steamers. It has a diecast, zamac boiler with brass details--is really good looking--and was offered in the As-Built USRA Version and the 1930's rebuild (with large BL feedwater heater on the left side) N&W version that also went secondhand to UP, ATSF, and third-hand to Virginian during/after WWII.
Most importantly, the Powerhouse 2-8-8-2 has the exact same Samhongsa mechanism found in the $2000 brass articulateds of the period--excepting possibly the soldered on crank (which is good--it can't come unscrewed).
Alternatively, go to the BLI website and buy the factory refurbished Y-6B at $330 (mine was perfect, good as new, and being "refurbished" was thoroughly checked out by BLI).
"You still get what you pay for."