Originally Posted by bostonSENflyer

there is virtually no benefit. No complementary upgrades, nor free economy + seat assignments. You may use Red Carpet lounges, but you are better off not even entering them :-). Regarding redeeming LH miles on UA flights, its possible, but UA keeps their saver award international business/first inventory pretty restricted. Also LH charges you fuel surcharge (~ 300 USD per long haul segment).