This was the first Bachmann locomotive to come with a dual-mode factory-installed decoder (it will operate on both DC and DCC layouts). And although a terrific looking model with fine paint and detailing, it does have its minor issues in the performance department (more on that in a moment).
The split-frame chassis is all metal and quite hefty. The motor is a closed-sided can. And although Bachmann advertises these models as having 5-pole / skew-wound motors, it's actually 3-pole and straight-wound. Dual flywheels are mounted to the driveshafts on either side of the motor. However, they are quite small (and to be honest, pretty ineffective). All wheels provide pickup (no traction tires). Current reaches the decoder board by way of long metal wipers that extend upward from the trucks, through the chassis, and ultimately brush against contacts on the bottom of the PC board. All wheels are geared and all gearing is plastic. The couplers are chassis-mounted Rapidos (easily replaced by MT's). Wheels are blackened and low-profile (no problems on Code-55 rails). Directional, bi-color lighting is provided by LEDs mounted on either end of the chassis. Said lighting changes from white to red when changing directions.
The pantographs are quite impressive. Sturdy, sprung and adjustable, these may well be the best pantographs I've ever seen on an N scale loco. More amazingly, they're actually functional. There is a small switch on top of the decoder board allowing one to switch from drawing track current to overhead current draw. A removeable roof section allows access to said switch, although I think it's probably easier to just pull the whole shell off and get at it that way.
Performance is, for the most part, quite good. Overall it runs smoothly and quietly. Pulling power is impressive. And although a makeshift insert tucked away in the box advises that these are best run on curves no sharper than 19"-radius, I haven't actually experienced any difficulties operating mine on curves as tight as 9.75"-radius (although the same probably can't be said for the long passenger cars it was designed to pull). On the downside, slow-speed performance is not particularly impressive. When faced with low throttle settings, mine goes all hummy and buzzy on me before grudgingly starting to move. And overall there just isn't much subtlety on the low end of the throttle, with even minor changes in throttle settings making for pretty drastic changes in speed. Clearly this model was not designed to be doing a lot of delicate switching. The problem is (for whatever the reason) even more pronounced when operating in DCC mode (where slow-speed creep basically ceases to even be an option). Further (and as alluded to above), the tiny flywheels are pretty useless, as these models tend to start and stop rather abruptly. Lastly, the top-end speed is pretty insane (and I mean like Nascar insane).
So, a respectable if not overwhelmingly wonderful model. But certainly good enough to include in an operational fleet.
To remove the shell, use a couple of toothpicks to spread the shell sides apart at the fuel tank. It should slide up and off readily at that point.
Reviewed 10/06 Model Railroader ("This N scale Amtrak HHP8 comes ready-to-run and is factory-equipped with a 28 speedstep automatic dual-mode DCC decoder. A vent panel on the roof conceals a sliding switch that changes the model from track power to overhead catenary power collection. Equipped with a five-pole motor and weighing 4 ounces, our model pulled 6 to 8 passenger cars. The HHP8's motor growled noticeably at slow speeds, but the model ran smoothly. Although the HHP8 easily handled 11" curves, Bachmann's 19" recommended minimum radius is presumably dictated by the model's body-mounted Rapido coupler and its intended use hauling scale-length passenger cars. The shell has excellent paint and lettering. Details include metal pantographs, recessed grabs alongside the doors, and air hoses and MU cables on the pilot. The lighting is directional, with the bluish-white forward-facing headlights on and the trailing end headlights off, replaced by illuminated red markers. $171")