All the "changes" I've experienced have been generally in a more positive direction -- I feel much calmer / less unhinged, even my full-blown panic attacks have been more controlled with less screaming and crying than before.
Other than that -- no noticeable changes to my personality. Some guys told me that I'd be completely unable to cry, but this has not been the case at all. Some told me that I'd be an unhinged ball of anger, but this hasn't been the case either. I was even told that my creativity would "die", but this couldn't be any further from the truth.
Any perceived changes are simply the result of a) feeling more at ease with being perceived as oneself, or b) purely psychosomatic changes occurring because of one's pre-conceived notions of what testosterone "will do" and what masculinity "is". I've found Max Valerio, for example, dead right about a few things, but dead wrong about others. If testosterone made all of these sweeping across-the-board changes to everybody on FTM HRT, then I wouldn't be able to name people (myself included) who've never had these experiences post-HRT.
Testosterone will not change your personality any more than you want it to.