This article indicates that terminating parental rights is better to create stability for a child:

http://adoptionlawfl.wordpress.com/2009/07/06/florida-court-adoption-over-permanent-guardianship/

It is a shame that no one has created a means of preserving language or history so that we can have consistency in our laws. If only there was some way. Something like... I don't know... language, but written down.