I'll admit I'm something of a conservative when it comes to this - I'd prefer to access donor milk through a milk bank rather than take the chance on someone else's lifestyle. I'd have to know them extremely well to consider using donated milk from them.
I feel this way atm but haven't been faced with the decision of using donor milk.

TBH it never entered my mind with my DD who was FF. I don't recall donor milk being offered as an alternative.... Something perhaps people should be directed to prior to being offered formula. (I had DD in a private hospital)