As you can see, the tender wheels (which scale out to something like 16" diameter - not even remotely prototypical) are more like little rollers, not wheels. The relatively large diameter axles (which are cast from white metal) fit into the holes in the wheels. The small wheel has a hard time actually turning on those large diameter axles and on many factory models those wheels simply slide on the track without actually rolling! Then the power from the axle assembly is transfer to brass strips under the tender by very fine springs. This results in a poor pickup (which is exaggerated by the very short wheelbase) and lots of drag on those "roller" wheels. Other than that, this locomotive is acceptable (if one ignores the black plastic leading truck wheels which also seem to be about 16" in diameter).
Peteski,
As Chris pointed out, you are complaining about something that Bachmann basically got right. The tender wheels on these things were small. When you take into acount the flange size and how low the tender needed to set, the wheels are about as big as they can be. There are plenty of variations of the American loco, some had large tender wheels, some had small. They model they chose, happens to have small tender wheels.
The pickup on the most recent versions changed the metal that the tender axle chunks are made of. They are now plated and the tender wheels roll much easier. The only thing wrong with the spring pickup is if you stall one on a turnout, those springs turn into a lightbulb filament pretty quick, soften up, and loose any semblence of being a spring.
Could it be made in a better way, YES. Is it the only option out there available for sale at this time, YES.