before I knew more about them and opinions on them....thankyou Mumsnet, I ended up using a half check collar with my lab but not as a choke.
It was used with a kumfi, as a dog trainer really helped me out after she became dreadful on the lead after being attacked whilst on it 
I still use a half check collar when out with her but don't use it, as a simple "back" command corrects her if she goes ahead. The reason I am still using it is because I have tried other collars and she hates them. She only wears a collar when out the house and only seems prepared to accept this type now.
As I am not misusing it, and she is happy and I am happy is this ok, or can you think of alternatives that she would accept?
Well done for getting this far.