fascinating tie really..... i think individually United have better players, but they still have a soft under belly..... cohesively Arsenal on their day can get it right and play high energy football, which could dismantle this United defence....
It won't be fire and thunder of 20 years ago, i imagine more likely the result will depend on which side makes the least mistakes....(sounds cliche i know!)
I think both teams are vulnerable to capitulating - so whoever scores first could be decisive.