The USA NW-2 has been out for a number of years.  It is one of the
first diesels produced in large scale (1/29) by Charles Ro.  This unit
was produced by EMD in the 1940's, and was sold to almost every railroad
in the country.  The locos produced 1000 HP and were available in
"cow & calf" sets if desired. ( The cow was the unit with the cab, and
the calf was an non-cab unit mu'd to the cow.)
     These diesels were used in major switch yards, branch line service,
and when joined as a cow and calf set, performed transfer work for many
railroads.  Many are still in service today, especially on branch line
operation.  The designation  NW stands for "new wiring" according to the
EMD handbook.
    This model is a fine looking, smooth running unit with great
detail.  USA has  painted this diesel in a variety of road names, and
the graphics are crisp.  As usual, all pilot details have to be added
by the modeler. Once again I would suggest using a photo of the
prototype, and a good quality CA-glue to keep the details in place. 
This is especially true of the air hoses, where you have right-hand and
left-hand hoses.
    USA ships the loco with  hook and loop couplers, and includes their
knuckle coupler.  Kadee makes a coupler conversion kit for this loco
(#787)   I have converted two diesels so they will mate with other
brands of rolling stock. Unfortunately, USA's knuckle is really not
compatible with any other brands. The rear of the Kadee coupler box
has to be shimmed so that the coupler reaches the correct height on
the coupler gauge.  I am not happy with this, and have let Kadee know.
I feel that the coupler should be higher on the mount so that this
shimming is not required.
    The control switches for the lights, smoke, and motor are under
the intake grill on the front of the unit.  It is quite simple to open
this grill and set the switches the way you want them.
    The switcher comes with lighted cab interior and an engineer. 
While I realize that they are all members of the union, I will definitely
repaint him so that he doesn't look like all the other engineers used
by USA and Aristo.  I will also add a 2nd figure to the cab, since the
contract did not allow these units to run with only one crew member.
    This diesel is a trouble free loco that does not require any
"tweaking" to make it perform well.  It does have those troublesome
pickup shoes which snag on the old Aristo wide-radius turnouts. LGB
makes a wider shoe that is a direct replacement which will eliminate
the problem.  In a rare case of cooperation, USA is planning on
producing a wider pickup shoe,  and Aristo has redesigned the frog on
its wide radius turnouts so that the shoes do not snag.
    This unit will look right at home on any layout, and will negotiate
short radius turnouts and curves easily.  USA offers a sound unit
manufactured by PH Hobbies for this loco which is easy to install. 
Other sound systems are available from Sierra and Phoenix.