Ok - the questions posed by Valerie-Elizabeth and Janet specifically.
Yes personally I think telling a partner is advisable, in just the same way that you might wish to tell them of anything else about your past. True love is about sharing and honesty, it is about connection. A life partner worth having will be the one person in the world with whom you can be absolutely honest and most truly yourself. If you can't trust and connect with them enough to tell them the inconvennient parts, your dark side if you like, then it isn't much of a relationship.
In regard to public stealth however, that is a very individual decision.
For myself I chose to go fully open a while back because I felt that it was time that those around me saw that, postop, we can become successful and fully integrated in society. The measure of my success in that is that although many people around me are perfectly well aware of my past, and although I make no effort at concealment, new people coming into my circle very rarely realise or are told about it unless by me. In other words though many people around me do know, it has ceased to be an issue or indeed anything they consider worth telling anyone else. To put it another way they now accept that a woman with a trans history really IS a woman at the deepest and truest level.
So from my personal perspective it has not been a choice between peace and being an uncomfortable trailblazer, sacrificing my life free of pain and anguish for the greater good. My life is already as peaceful and comfortable as it can get. If it wasn't I probably wouldn't be so keen to be seen for what I am nor would I be on sites like this.
It is precisely because I am well integrated into normal society that I am keen for others on both sides (those with no experience and those with a full trans history themselves) to see that far from being isolated and considered freakish a postop CAN be known for what she is and yet accepted on equal terms with a natal female!
Ironically I sometimes think that it is actually more difficult for those in the trans comunity to accept that fact than for those outside. But it is true I promise. You CAN have it both ways if you really want to.
But as I say, it's an individual decision and not one which any of us has the right to criticise others over. Each of us must do it the way we feel comfortable with.