I have the grinding noise too. Whether or not it makes the car live as long we will only know when that bridge is crossed. What needs to happen for us to remain satisfied is to have ford fix the damn thing.
Its not a 'normal' noise. It's not a manual transmission noise unless you don't know how to drive a manual. It only does it between certain gears, so it clearly works during some shifts.
I love the car. But it needs to get fixed. I'm waiting to put more miles on mine - the dealer already documented the noise and know it does it - before I go and try to get them to fix it.