But I'm going to guess (with a high probability of being correct) that you probably didn't have to exchange an actual biological child for the adoptive one you now love and cherish.
What emotions might come up for you around this exchange? Sadness? Anger? Confusion? I imagine you might experience a complex mixture of emotions at best. Even if you came to love the replacement child, would you not still feel the loss of the original one? What emotions might come up for you each year near the anniversary of the exchange? Even if you still got to see the first child sometimes, if you knew where he or she was and got to exchange gifts, make phone calls, and even Skype, wouldn't you still miss the child? Or imagine that you were reunited with the original child years later ... would you not you not still grieve the lost years, years you could never get back? Can you even imagine that in some ways, you might never fully recover from the loss of the first child, regardless of how much you might love the second?
When adoptees speak of loss or pain or trauma, we do not do so to be mean to adoptive parents or to make them feel bad about their families. We do so because this is our experience. Even if we appreciate our adoptive families, even if we wouldn't exchange the life we ended up with for another, loss is always a part of the equation for us.
And then there are the original parents ...