Owned both; sold HS2 fairly quickly, still own DW.
HS2 got stale fast due to its lack of depth and the fact that its shots are fairly easy to make. After a month its repetitiveness bored me, every game was the same. Dont even get me started on how annoying the zz top will get after awhile.
DW has so much more depth and it has a thrill of trying to keep up your multipliers or sustaining combos, both are necessary for good scores. Its a much harder game to consistently score well vs HS2, so better for home ownership imo. Plus the time expander is one of the best toys in pinball!
They made twice as many HS2 so id grab DW if both are available, it will be easier to get a HS2 anytime.