They are both better than CO elite status for international travel which was my main point. Between themselves, you are right in that American provides elite bonus points for all partner flights. But UA, at the moment, has something more valuable to people like me. All paid miles on alliance flights count towards Elite levels. As far as I know, no one else does this except for some specific partner flights like CO/NW/KLM. Given the number of major carriers on Star Alliance, this is extremely useful. BTW, AA does not even give mileage credits for transatlantic flights on BA let alone elite bonuses.

Which brings me to the second comparison -business lounges. Normally, you get good lounge service in airports where the participating airport has a major presence. In other airports where a participating carrier has an arrangement an airline not part of the alliance, you will not get the lounge privileges.

For example, although British Midland (part of Star Alliance) flies to Nice, France, it only has an arrangement with Air France for its FF members and does not have a Star Alliance lounge. I don't get lounge privileges there. In general, an alliance that has more major carriers with its own lounges in airports (and hence can accommodate alliance members) is better than an alliance which has fewer major airlines even if they happen to fly to all the airports. *Alliance has an advantage here over One World because of their more extensive partnership with major carriers. This is particularly noticeable in Europe and Asia. Of course, if you fly only from airports that has a major presence of AA, then it wouldn't matter.

Cheers