I know the OP is probably not even reading any more, and of course this thread has inevitably become a CIO or not to CIO thread, but I have to add my 2 cents worth.
I completely agree that all babies are different. There is no way my dd would have slept through at 6 months. She was too hungry. We did BLW, and she was a good eater, but amazingly active (crawled at 5.5 months, walked at just under 10). She could go to sleep on her own with no difficulty at all, but she would cry for 3-4 hours at night if she woke and promptly stopped when fed. We did sign language with her and at just over 12 months after I had let her cry for a while she made signs for more food! I took her downstairs and she ate half a cooked chicken breast and immediately went to sleep on her own, no milk. My instincts throughout this time were that she WAS hungry. I think that you have to listen to your instincts. Some posters have said they KNEW it couldn't be hunger; I knew it had to be, but nonetheless spent huge amounts of energy worrying about it!
She began sleeping through at 13 months and now, at 20 months, we simply never hear from her unless she is sick. We gave porridge at bedtime from about 13 months and that might have helped. I bf'd till 18 months.
I am pg again and am simply not going to worry about sleep! If the baby can put himself to sleep at bedteim about 5 months, then that's my job done.
All babies are different. If you are coping with night waking, then I wouldn't worry about it. If you are not coping (have to return to work, can't sleep during the day, etc) then it might be different.