Once you find the right position for you, you should consider replacing it with a fixed stem that holds the bars where you need them.

Adjustable stems are heavy, and when you stand up to climb, you put a lot of your weight on the handlebars. The adjustable stem shouldn't snap on you, but it's disconcerting to feel it creak a little bit. Don't try to tighten it down too much; that won't help, and you can break the bolt if you try hard enough. (Ask me how I know...)