Hi 1cay,
you might want to try posting this on the UA board. As far as I know, there are no additional benefits. Generally speaking, if u do mostly domestic or fly CX across the pacific, then I would look for a comp to Platinum on AA (100% bonus miles plus class of service) and then work on getting highest tier with OneWorld. If you fly often across the Atlantic, then look into attaining Senator status with the Lufthansa Miles and More program. In any case, the individual boards would offer more insight. Are you Million Miler yet with UA?