Methinks you're being a tad over-fussy now.
They are both old cards and tbh I don't think you'd really see much difference in performance between the two.
From the period when those cards were manufactured Nvidia were making better graphics cards, imo.
So, despite the ATI's specs being slightly better, I'd actually use the 5200, it's an excellent little card.
I don't know anything about this 'digital vibrance' sounds a little risque to me, tbh