Giving up your humanity

As we creep towards a post-human/trans-human future I am beginning to wonder not just what we will add to ourselves, but also what we choose to take away. Beyond the obvious elimination of disease, what else will we remove from our current selves? In a sense disease is a good place to start. We normally distinguish between physical health and mental health, but in reality there is a spectrum between the two. And it seems to be that there is a spectrum between mental health, personality, motivators/desires and intelligence.

So, would I give up or alter my personality? Or what motivates me? I am inclined to eliminate bias from my thinking in the first instance. I suspect this will have a profound change on my personality in itself. But I also inclined to meddle with my motivators. Perhaps reduce the desire I have for sugary food (perhaps it could be argued that the battle against this desire is advantageous for its willpower side effects - suggest this needs research). Perhaps increase the satisfaction I get from learning something new, or from doing exercise. These modifications seem without significant downsides. But what of changing your own sexual desire? There is no doubt that extremes of sexual desire have led people to acts of stupidity and evil. But sexual desire also seems to be something that is "human". What of changing ones own mechanism of attraction to emphasize the physical less relative to other characteristics.

If we do make such changes would we regret making them? Or would we be so different a person as not to be able to relate to our former selves? Is such a process reversible?