I'm so happy to have found this forum, so many of the other ones I've looked through have a clear objection to free-flighted birds "It's not safe, it can't be done, you're puttng your bird at too much risk" etc...
My blue Indian Ringneck Parakeet and Doves have been fully flighted for several years now and not once have I ever had a problem with injury, escapes, or the usual "dangers" people whine about.
My entry way has 2 sets of doors, so even guests who are unaware of the flying critters in my home would have a hard time facilitating an unintentional escape.
I've recently acquired a female blue & gold macaw who was clipped by her previous owners before coming to me, so now I'm waiting on her flights to grow back in... though she is a pretty powerful glider so she does still have some of the wing strength necessary for flight (They told me she had her own room, and was flighted before and could fly) I'm taking the opportunity to work on her basic training right now, clicker/target/etc.