Please be careful about investing with DL. Their award availability is horrendous. They were ranked second last in a WSJ survey:

http://www.flyertalk.com/forum/delta...ilability.html

Do a search in the DL forum, and you will see how bad it is. If you do have the misfortune of flying DL, at least credit the miles to AS. AS is a partner of AA and you can redeem on AA.

Do not believe the negativity of US per the WSJ. US is a Star member and is a partner with UA, CO, AC and many others. You can redeem on these partners which have been highly ranked by WSJ.