Mechanically, these models employ a design very much in keeping with the conventions employed by Atlas in their diesels. In fact, Intermountain and Atlas diesels appear to actually share many of the same internal components (motor, etc). Just speculating here, but I assume this means that they were made at the same Chinese factory that Atlas uses.
The mechanism sports all the features one normally associates with "modern" diesel models - IE, DCC-Ready / split-frame / all-metal chassis, 5-pole / skew-wound / "slow speed" motor, dual flywheels, low-friction drive, bi-directional LED lighting, all-wheel drive and pickup (no traction tires), blackened / low-profile wheels, shell-mounted Accumate couplers, all-plastic gearing, etc.
Performance-wise, this locomotive is perfect. Smooth, quiet, responsive and powerful. Excellent slow speed creep and reasonable top-end. On the downside, I find the paint to be a bit heavy looking in spots. Nothing horribly noticeable, but definitely not as sharp and fine as an Atlas or Kato. Like other Intermountain diesels, all of the various shell pieces are glued together. So disassembly (for painting purposes) is not as easy it could/should be. Fortunately, they don't appear to be as flimsy and prone to falling apart as the earlier Intermountain "Tunnel Motor" models. Decoder installation is fairly simple, and the procedure is exactly the same as installing a decoder in an Atlas diesel (IE, you have to de-screw the two halves of the frame in order to install the decoder). Overall, these are fine looking and great running models.
Having said all that, I'm told that there are indeed a few "rivet counting" type issues to worry about (for those that worry about such things).
- No gap between the dustbin hatch and exhaust hatch
- No beads on the blower ducts
- Incorrect fuel tank (first run only - fixed on subsequent runs)
- Incorrect sill cutout (too short)
- Various profile height inaccuraciess on the EL/CR version (the dustbin hatch, exhaust hatch, dynamic fans, engineroom vent and radiator fans are all supposed to be low-profile - and they're not)
Trivia - SD45-2 shells will fit on IMRC's SD40-2 chassis (a quick and easy way to add DCC-Sound to your SD45-2). Kato's SD40-2 chassis is reportedly a good fit as well.
Shell removal is blessedly simple - just take hold of the fuel tank with one hand and the shell with the other. Then, just sort of wiggle it up and off.