If you like being nit picky... you should note the two "or's" in MossRoad's definition. By your own admission it looks "handy", "nimble", "practical" and "variable in it's abilities". That sounds like a machine that could "inspire respect through being impressively capable".
It sounded to me like much of your opinion was based around the PT4xx's size. They actually do weigh quite a bit, and when matched up against the average person's home tractor they could be considered "impressively large, powerful, intense, or capable" in comparison. The work-to-size ratio is probably very high when compared other tractors. I'm curious though... do you consider your tractor "formidable"? How about when it's up against a D10?

Point being... everything looks small when next to something bigger, and its all relative to what it is being compared against.
That all being said, formidable is the not first word that I would pick to describe the PT4xx, but IMHO the average person would not be crazy for thinking it was.