I think way back I posted in this thread, for me as long as the checks are done, as long as the childs welfare and security are assured as in 'all' adoptive relationships and checks into same, then all that matters to me would be the child's right to a stable home and future, so I can see no argument whatsoever as to why gay adoptive parents should not be permitted.
Actually likely more goes wrong in other adoptive scenarios than in gay relationship ones.

Yes, does not matter about the gender of the couple as long as the correct checks are done and that the child is in a loving and positive environment.. although of course you will get some children with problems, which can be dealt with in time...