An upgraded 6180DN
This by all means is just an upgraded 6180DN.
Got one here. After 25K pages the jam-count is still zero. And I can attest to the printer lacking the slow-down feature in its duplexer, quite simply because it's designed to handle up to four pages in memory at once.
Be adviced that photo printing is best served with the PCL driver if printing from lightroom (the PS driver uses real CMYK output and Lightroom chokes on the ICM)