I'm one who doesn't want a label for my child. It's only in the last few weeks (since I have taken him out of school to home educate him) that I have had my lightbulb moment and realised that he has asd. It's something I have been aware of a a possibility since he was very young, and I thought he seemed to be functioning pretty normally. However, he is 7 now, and I can no longer stick my head in the sand.
He's academically bright, but his social skills are pretty poor. His behaviour has always been difficult to manage, but I thought for a long time that this was due to his father's very poor parenting (happily, I have been a single parent for over a year now).
I don't think ds1 would get a diagnosis very easily - he presents as too "normal". I'm probably the best placed person to help him - I have a lot of coping strategies as i am almost certainly on the spectrum myself, but only realised this when I got a job providing 20 hours a week 1:1 classroom support for a little boy with Aspergers - that little boy did extremely well under my care, despite his teachers trying to use all sorts of inappropriate strategies, and his mother was no end grateful to me.
In my view, a diagnosis is a route to getting appropriate support. I can provide appropriate support much more effectively than the school or camhs etc. (In fact, when I asked for support from camhs because of his behaviour, their response was to recommend that I did a parenting course for mums of children who have experienced domestic violence - the same response my friend got, even though her little boy presents quite obviously as having autism and I think he needs 1:1 help at school).
A diagnosis isn't a magic bullet, and can stigmatise the child without the additional needs actually being met.
I know I'm rambling, but it is the middle of the night - sorry if I'm not making sense!