The Grizzly unit I have seems to be a decent machine. It will hog off material without a burp and was set up very well from the factory.
I can't see any real world benefit to a top motor design that would have me leaning toward buying one. If it was a real US built unit for an extra $400 for me it would be a no brainer but that isn't the case.
I would likely use the $400 for some other tool or put it towards a spiral head.
Joe
JC Custom WoodWorks
For best results, try not to do anything stupid.
"So this is how liberty dies...with thunderous applause." - Padmé Amidala "Star Wars III: The Revenge of the Sith"