I strongly suspect that even if you find one that has a sweet spot, DL will still end up being the better deal, depending on how you value your miles/dollars. Just as an example if DL offers US to China R/T fro 120,000 miles in C and only has $50 in taxes added to the ticket, or let's say GA charges only 100,000 miles in C but has taxes and fuel surcharges of $650, I personally value the $600 in my bank account much higher than 20,000 extra miles. This is assuming that all other partners charge YQ for CZ which I believe is the case.