Upon unwrapping, the first thing that stood out was the differennce in colour. The UK Mars was much lighter than the US Milky Way.
We cut some pieces to share and compare and could see there was less caramel in the UK Mars (on the left on the cross-sections above) and more chocolate on the sides of the US Milky Way.
There was a clear winner on the taste test, the US Milky Way was much better. We could taste the chocolate, caramel and nougat whereas the UK Mars was bland.