Again having looked SERIOUSLY at both I disagree. Also know if yo look at a big box store they do not sell the whole line of BK or units from Onward. You need to find a true "dealer". But while even the big box models are not "quite there" in some factors they cost about half as much and from my judgement should last about the same amount of time given a little care.
What specific models or onward brands are you referring to? There's so many it's a bit overwhelming for some of us.