Update:
The American Barleywine/IIIPA is really impressive. FG tapering off. Today it's at 5.8°P! Who would have thought that an 11.5% abv beer with no sugar, would reach 77.4% ADF in 10 days using just an active 1200ml starter? Amazing
The Imperial Stout is close behind at 6.4°P 10% abv and 73% ADF and appears to have reached terminal gravity in just 9 days!
Especially when you consider they started life at 60F