The last Duke died in 1636, with his line dying out the heir was his overlord the Elector of Brandenburg, through Sweden occupied the entire Duchy, but France forced/pushed Sweden to give the poorer Hinterpommern to the Elector of Brandenburg.
Pommern had been mostly depopulated (lost over 50% of the population) in the 30YW. The state was somewhat smaller than modern Denmark, through by the time of the Second Empire it had the same population density (it already seem to have reach that in the 18th century). The soil in general was of poor sandy quality, excellent for growing potatoes and cattle ranching but little else. The only thing of value was a few towns (primary Stralsund and Strettin). Sweden under its rule seem to either have mismanage Strattin or the trade network had broken down, because it lost most of it values under their rule. The central position in a united Duchy may result in it being adminstrative centre rather than Stralsund, which may resulting in it doing better.