I agree with the obsessional part - Ruby gets obsessed with certain things like her AirKong toy to retrieve; but I don't think she would make a good gundog, Dyson perhaps though: on second thoughts he's more likely to eat the bird instead of retrieving. A friend who has a few doodles has one who would be ideal as a gundog though.
I have a tiny JRT who thinks he is a gundog! He retrives and he quarters so I don't see why a Labradoodle should have any problems.