With your head, I'd lean more toward the PDoc to figure it out than the general practitioner, just because he's the "specialist." But, as you say, it's not an exact science and I think, as an engineer, you're still going "at it" like it is. It's not a "problem" in the sense you're thinking of problems. It's a continuum and there is a large area, over half, on the continuum that is "acceptable" according to what you please! Were I in your shoes with your background. I'd start being "scientific" with the medicines and recording mood charts (see: http://realmentalhealth.com/bipolar/.../moodchart.pdf from http://realmentalhealth.com/bipolar/chart_mood.asp as to how they affected you (whether you personally "liked" it or found it helpful, etc.) and make lists of behaviors, thoughts, and reactions of yours you don't like, rating them on a continuum and deciding what "number" you would find acceptable and work on those behaviors, thoughts, reactions in concert with the meds to see what benefits you most. That way you don't really have to worry about what "name" they give it or if it benefits some people but not others, etc. Mood charts often are about bipolar but they can work for anything, even normal people or personality disorders, etc. Can help you and your therapist know what to concentrate on and also your psychiatrist with the meds.

Good luck with figuring out what you want to know.