There's nothing wrong with the word. I like it. But it makes me cringe when it is devalued to mean the person I currently sleep with or the person I'm somewhat committed to. Sometimes it seems to be used to equate a same-sex sexual relationship with marriage. Another misuse.
My wife is most certainly my partner. By God's grace we intend for our partnership to last for the rest of one of our lives, though we wish it were for both.