Between 5 and 7 months was definitely the worst time behaviour wise for us, coincided with teething but not sure if related or not.
Pup is a star on walks at the moment, I've been walking her past people, bikes and dogs without jumping to put her lead on when I spot them in the distance. She still generally doesn't listen when out and about and is more interested in the world than any sort of training but she listens when it matters, i.e. recall so I can live with that for now. I can't even get her to sit unless it's on something these days (tree stump, bench etc.).
I'm hoping some of the gundog training will just click at some point. I'm sure a lot of it is down to my training ability/appetite, so much nicer to go for a walk than spend half an hour trying to get her to do some training exercises so I let a lot of things slide. I remember it took forever to teach her down on command rather than a hand signal and then one day she just got it.