I own 4 Rivarossi Big Boys, 1 PCM Big Boy, 1 Marklin Trix Big Boy, 1 Athearn Genesis Big Boy,
plus 1 Bowser Big Boy.
In brass I have 1 Olympia Gem Big Boy, 1 Sunset Brass(late series of Big Boy)
and 1 Tenshodo Big Boy.
If you are looking for the finest detail on a non-brass Big Boy then I recommend the
PCM (BLI?). The only detail they missed was the dual electric generator just forward of
the turret, and slightly to the left(it was not installed, and here was no provision for
the installation). None of my other locomotives held a candle to it regarding overall
detail and it pulled over 100 cars with no problem without traction tires. (note
that I added and adjusted weights)
My next choice would be the Genesis series in spite of their plastic construction.
The early Rivarossi units had pizza cutter flanges and undersized wheels and their
latest weathering effort is terrible. The newer Rivarossi do however run better than
the original units.
The best pulling effort is by the re-motored Bowser but even with the super detail kit
the Bowser lacks the finite features of any of the other models. The casting is just
too crude.
As far as a scale representation of the Big Boy, both the Trix(3/8’ too short) and the
Tenshodo(1/2+"too long) fail miserably. In both cases the problem seems to have
been caused by designing the units around driver issues.
The PCM, 1 Rivarossi , Trix, and the Athearn Genesis are DCC/Sound.
Again, two thumbs for the PCM Big Boy. It has rivet detail, latches and plumbing
features sadly missing on all the other Big Boy models including the 4015 Trix
(RP25 flanged).