After his trade to Orlando, or roughly after a year he proved that he's much more than a "human victory cigar". Look at Pistons, they're dying for a center like Darko. They should be regretting about their decision to send him.
But in my opinion, Darko completes Howard than he may complete Okafor. Okafor is a defensive-minded big man, so is Darko. But Howard is much offensive. Howard-Darko is a better combo than Okafor-Darko.
I believe we need a better offensive big, someone like Bogut. But I won't say no to a Oden-Okafor combo of course .