The DHC6-300+ mods:
More powerful engines. PT6A-34 @750shp.
Autopilot target altitude goes down to 100'.
More accurate sound.
Added ADF volume control.
Fixed thrust reverse.
Added landing and taxi lights (requires ALS).
Fixed intake deflectors.

Seaplane:
Fixed autostart when in water.
Fixed manual start. Added "Remove tiedowns" selection in Menu -> DHC-6