Well, I've been on the same dose for the past 8 years (set by my original endocrinologist and carried forward by all doctors since, who've basically shrugged and said "ehh, worked so far"). Last time I had my testosterone levels checked they were on the high end of normal, which suits me fine. I have a fairly high sex drive, which you might expect, but very low aggression, which you might not - although I've always been a very passive and non-aggressive person. So I guess to answer your question, I haven't really explored different amounts. I don't particularly plan to in the future, if for no other reason than I've been on my current dose long enough to self-identify with the range of behaviours it produces.