Nailed it.
Yes, our box technically is a "white box", but our support offering is just as good as the big guys. This isn't some frankenstein POS with no engineering behind it that needs the touch of the IT guy who quit last week. That's the difference.
That said, a white box can be made to be as good or better than the name brand stuff, particularly in the desktop department, but you won't get it for the price point you may want.
Bottom line: Support, price, or quality... pick any two.