After visiting Wismar and Stralsund as well as Lubeck this year, I am pleased that Lubeck is a separate WHS. Probably as a result of having been hidden in East Germany for several decades these two towns have retained their integrity as heritage towns. Very little modern construction is apparent, in fact some WWII bomb damage is yet to be restored, eg the Marienkirche in Wismar).
Saw both towns in a day, travelling by train between.