The "owning both" qualification slowed down your responses, Jonathan. 16 people have read your thread (counting you), but apparently can't meet that criterion.
I don't own either of them, but, fortunately, that won't stop me from offering an opinion
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The 85/1.8 isn't any "better" than the 50/1.8, but it would give you additional working distance and increase the degree of isolation you'd be able to achieve when using a wide aperture. The 85/1.4 is considered to the the cream of the crop in portrait lenses, but it comes at a steep price.